(via TheNewswire)

Melbourne, Australia and Vancouver, Canada – August 27, 2026 – TheNewswire - Mithril Silver and Gold Limited ("Mithril” or the "Company") (TSXV: MSG) (ASX: MTH) (OTCQB: MTIRF) is pleased to provide details of significant progress at Mithril’s district scale Copalquin property, Durango State, Mexico.

Drilling Highlights

• Recent drilling at the historic Copalquin Mine area at Target 4 has returned wide, high-grade, and near surface silver and gold mineralisation, with substantially elevated silver values,  

• Mineralisation intercepted by drilling across the combined Copalquin-Zaragoza corridor now extended to a strike length of 550 metres and 200 metres vertically  

• Projected vein remains untested 400 m to the northwest towards Target 1 (Refugio) and 600 m to the southeast towards Target 4 (San Manuel):  

  • 11.70 m @ 456 g/t AgEq 1 ( 1.06 g/t gold, and 381 g/t silver) from 22.0 m (CO26-001) , including  

3.40 m @ 1,239 g/t AgEq (2.72 g/t gold, and 1049 g/t silver) from 28.4 m, and including

0.60 m @ 3,877 g/t AgEq (4.81 g/t gold, and 3,540 g/t silver) from 31.2 m.

• • 13.95 m @ 387 g/t AgEq (1.76 g/t gold, and 264 g/t silver) from 88.85 m (CO26-002) , including  

1.00 m @ 1,747 g/t AgEq (7.03 g/t gold, and 1,255 g/t silver) from 97 m.

• • 6.50 m @ 320 g/t AgEq (0.22 g/t gold, and 305 g/t silver) from 93.4 m (CO26-003) , including  

0.80 m @ 1,890 g/t AgEq (1.07 g/t gold, and 1,815 g/t) silver from 97 m.

This latest drilling includes higher silver grades and builds on successful results from June 2024 when the first drill holes in this area returned intercepts, including 5.66 m with 2.58 g/t gold, 230 g/t silver from 18.5 m in drill hole CDH-152 2 .  At the time, the geology of the area was not well understood. With the benefit of this new drilling, combined with the high-grade results further along strike at Zaragoza, including 0.57 m with 6.40 g/t gold, 4,400 g/t silver from 342.4 m in drill hole MTH-ZG25-37 3 , the Company is working to determine grade continuity within the Copalquin-Zaragoza Structure, which has a potential total strike length of 1.5 km (see Figure 1 ).

Drilling has now confirmed mineralisation over approximately 550 metres of strike length and remains open for potential expansion both along strike and dip (see Figure 2 ).  This growing zone is interpreted to form part of the Copalquin-Zaragoza Structure, a major northwest-trending geological feature that may connect El Refugio at Target 1 with the historical San Manuel workings at Target 4 across the valley to the southeast.  

“ These results represent an important step forward in our progress at the historic Copalquin Mine area within this large, high-grade gold-silver system. What began as an area with limited geological understanding has progressed with potential to be a substantial, high-grade mineralised corridor, with drilling demonstrating strong gold and silver mineralisation over a substantial strike length and across multiple levels,” said John Skeet, Managing Director and CEO.   “The combination of these broad mineralised intervals with exceptional high-grade intercepts at the Copalquin mine area and our results further along strike at Zaragoza is particularly positive. We are seeing how these discoveries potentially align within the larger Copalquin-Zaragoza Structure and connecting several historical mining areas across the district.  Drilling has recommenced at Target 4 to test the structure to the southeast”

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Figure 1 : Target 1 plan map showing drill hole trace locations, highlight intercepts in this announcement and resource footprint area

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Figure 2: Long section view of the El Refugio vein looking perpendicular to vein to the northeast

ABOUT THE COPALQUIN AND LA DURA GOLD SILVER PROPERTIES

Mithril is undertaking an aggressive exploration program in 2026, with 25,000 metres of drilling planned during the year across the Copalquin District . Work in the second half of 2026 is focussing on expanding known mineralised zones, testing new high-priority targets, integrating district-wide geophysical data, and continuing to advance the Company’s district-scale exploration thesis.  There are 13 target areas with 6 of that advancing as high-priority and including the recently upgraded resource at Target 1 4 . The district features over 100 historic underground workings including several notable past-producing multi-level mines and small 200 surface workings (c.1850 – 1910) .  Mapping and sampling across the lower half of the 70 km 2 mining concession area demonstrates and a large epithermal silver-gold system with multiple target areas for potential resource growth plus the conduit system responsible for the widespread silver and gold mineralisation. Of note, are the persistent and widespread high gold grades, sampled across this silver district.

Figure 3 : Mithril’s Copalquin and La Dura property locations in Durango State, Mexico

The northern half of the Copalquin concession area features large areas of alteration. The LiDAR image shows evidence of historic mining activity and indicates some key structures.  Along with historic sampling data, the northern section of the property presents as a potentially significant large exploration area within Mithril’s Copalquin mining concessions.

Mithril has an exclusive option to purchase 100% interest in the Copalquin mining concessions by paying US$10M on or any time before 7 August 2028.

The nearby 20 km 2 La Dura property has recently been added to the portfolio providing a brown field property with a database of mapping, sampling and drilling 5 .  The recent LiDAR survey 6 has revealed multiple historic workings within the concession area, including the 4-level high-grade La Dura mine.  An initial 1.5 km long mineralisation corridor has been identified as a future drill target.  An aerial magnetic survey has been complete with interpretation work currently progressing.

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Figure 4 : LiDAR identified historic workings across the 70km 2 district. Current drilling locations at Target 3 and Target 4 with ongoing mapping and sampling.

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Figure 5 :  Property-wide channel sampling results for the middle and south district sections within ~50% of the 70 km 2 mining concession area covering the Copalquin District. An aerial magnetic survey and a desktop structural study have been completed over the area and are being interpreted to support drill planning for district defining targets such as the current drilling along the Copalquin Structure.

Drilling Program Discussion

Table 1 : Recent significant results received for Target 1 resource upgrade drilling

* Intercepts shown on attached maps and sections

** Copper (Cu), lead (Pb) and zinc (Zn) values are shown for information only and are not included in the calculation of AuEq nor being considered as part of the economic model for the deposit by Mithril.

 
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Figure 6 : Target 1 plan map showing drill hole trace locations, highlight intercepts in this announcement and resource footprint area

Copalquin-Zaragoza Drilling Summary

The Copalquin Mine is located on the northwest margin of the Copalquin arroyo just above the site of the historical San Manuel 10 tonne per day mine (Figure 7). There are two tunnels driven at 290 degrees on a 0.4 to 0.8 m wide quartz vein that dips steeply to the northeast.  The longer of the two tunnels is 30 m in length and has no stopes.

Matrix supported hydrothermal breccia with black sulphide is observed in the vein in the workings. The vein is in the centre of a 15 m wide zone of similar thinner veins forming a structural corridor.  Channel sampling returned assays grading up to 7.48 g/t Au and 300 g/t Ag, over a width of 1.2 m.  In 2024, drill holes CDH-151 and CDH-152 were drilled immediately below the workings to test the down dip continuation of the high-grade mineralisation, and holes CDH-154 to CDH-156 were drilled to the northwest and along strike of the workings.  The best intercept was in hole CDH-152 grading 1.92 m at 4.50 g/t Au and 520.2 g/t Ag starting from 18.50 m downhole.  Drill holes, CDH-151 (partially), -155, and -156 intercepted what is now understood to be a post-mineral dyke system (Tapp) at the projected vein intercept depths and that were previously interpreted to terminate the mineralization.  

Across the ridge to the northwest in the Soledad arroyo, the Zaragosa workings appear to be on the same structure (Figure 7). The Zaragoza workings are completely caved and inaccessible but are shown on historical maps to run at 105 degrees directly towards the Copalquin mine 300 m to the southeast. Both tunnels are developed in granodiorite.

In 2025, four holes were completed at Zaragoza as an initial program to undercut historical workings (with channel grades up to 0.75 m with 3.46 g/t Au and 1,190.0 g/t Ag) that were thought to be the possible northwest feeder structure of Target 1. The drilling successfully intercepted high-grade gold and silver approximately 130 m down dip from historical workings. The best drill hole returned assays of 6.4 g/t Au and 4,400.0 g/t Ag over 0.57 m starting from 342.4 m depth in hole MTH-ZG25-37.  Hydrothermal vein and quartz breccia zones with anomalous Au and Ag were intercepted in holes MTH-ZG25-39, 40 and 42.

Based on the positive results of previous drilling and new interpretation of the post-mineral dyke system (Tapp) that was applied in the Refugio area9 , three drill holes (totalling 528 m) have been completed to test a revised interpretation of the Copalquin structure.  All three drill holes successfully intercepted the target structure within the host granodiorite unit.

The three holes were drilled to test the projected extension of the Copalquin vein along strike, and at similar elevation, and across the post-mineral dyke intrusions (Tapp).  Hole CO26-001 was the first hole to be drilled on the east side of the Copalquin arroyo as a 60 m step-out from hole CDH-152 and successfully intercepted the Copalquin structure in a 11.70 m wide (downhole length) hydrothermal vein and quartz breccia zone.  Drill hole CO26-002 was a 120 m step-out to the northwest of hole CDH-156, and 70 m step-out to the southeast of hole MTH-ZG25-42 to bridge the connection between the Copalquin and Zaragoza structures, and also successfully intercepted a 13.60 m wide (downhole length) mineralized hydrothermal quartz breccia.  Hole CO26-003 moved back to the southeast as a 60 m step-out from CO26-001 and successfully intercepted two zones of mineralization, with the upper zone partially truncated by the Tapp system and the lower zone spanning 6.50 m (downhole length) of mineralized quartz breccia and stockwork (see grades reported in Table 1).  

Anomalous base metal mineralization was intercepted in all three holes, occurring at generally low concentrations and dominated by zinc and lead, with less common copper (present as chalcopyrite). Based on other drilling results in Target 4 and Target 5, the granodiorite (Tgd) commonly exhibits elevated base metals and silver within polymetallic mineralization. This base metal association may reflect a polymetallic component of the deeper or lower-temperature expression at the base of the broader epithermal silver-gold system.  

The program successfully expanded the known footprint of the Copalquin vein along strike at a consistent elevation of approximately 850 metres above sea level, successfully bridged the Copalquin and Zaragosa structures over approximately 500 m of strike length, and identified drilling targets in all directions along the structural corridor.  Untested ground exists to the southeast along approximately 600 m along strike and 350 m up-dip between CO26-003 and the historical San Manuel mine, and to the northwest along approximately 400 m of strike with 250 m up-dip of untested ground between MTH-ZG25-39 towards the El Refugio zone (Figure 9).

 
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Figure 7 Copalquin Structure plan map showing drill traces along 500 metres of strike and recent drill intercepts

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Figure 8: Cross section +/- 100 metres for drilling on the Copalquin Structure

Figure 9: Long section view of the El Refugio vein looking perpendicular to vein to the northeast

Other drilling results discussion

Since completion of the Target 1 Mineral Resource drilling program in June 2026, Mithril has been leading an exploration drilling campaign to test geophysical and structural targets.  The program has been advancing methodically moving from west to east.

Four holes were completed at El Refugio (2 holes, 1,038 m) and La Soledad (2 holes, 723 m) following the cut-off date of the Target 1 Mineral Resource Estimate.  The holes in Refugio tested down dip extension of the vein, with hole RE26-017 successfully intercepting mineralization in 2 zones At La Soledad, drilling was completed to test the southeast extension of the vein, with several notable intercepts (see Table 1 ) within a narrow and stockwork mineralisation.  

In the Refugio west area, five holes were drilled at El Gallo (2 holes, 462 m), La Guacima (1 hole, 228 m) and El Platano (2 holes,1,143 m) areas.  The program intended to test the western extension of the Refugio vein between the Mineral Resource area and El Gallo. Presence of the Refugio structure was intercepted in drilling, however mineralization contained no reportable grades.  El Platano, located to the northwest of the Target 1 resource area, consists of a zone with strong argillic alteration and which appears to lie along a northeast trending structure.  Drill hole EP26–001 targeted intersection of this northeast structure at the top of the hole as well as geophysical anomalies to depth which were explained by Tapp intrusions.  Drill hole EP26-002 was drilled to overlap with EP26-001 at a higher elevation, and to test for the continuity of the westerly projected Refugio structure at depth. Hole EP26–002 successfully intersected the Refugio structure between 306.05-311.60 m downhole depth as a brecciated zone with light grey hydrothermal quartz and minor sulphides, and with anomalous but non-reportable grades.

In the Target 5 area, drilling was completed to test the depth and northwest extension of the El Apomal (3 holes, 865 m), Las Lianas (3 holes, 513 m), and La Maquina (1 hole, 234 m).  The Apomal holes intercepted quartz breccia structures at the projected depths however did not contain reportable grades.  Of note in hole AP26-003 was a semi-massive sulphide intersection, within a northeast trending structure, with 6.2 m of 0.58 % lead and 0.55 % zinc from 200 m, including 1 m with 2.62 % lead and 1.61% zinc from 205.2 m.  While base metal mineralization is not a pursued interest by Mithril, the intercept offers insight into the broader mineralized system in the Target 5 area.  At La Maquina, hole MA26-002 was a follow-up to the success of the discovery hole MA26-001 10 .  Hole MA26-001 was drilled as a 150 m step-out to the northwest and successfully intercepted the structure approximately 100 m below surface.

A summary of all holes being announced in this News Release is shown in Table 2 , with a complete list of all assays >0.10 g/t AuEq listed in Table 3  .

Table 2 : Drill hole collar details included in this announcement

Note:  Some collar locations may be reported with approximate handheld GPS coordinates, while surveying with differential GPS is pending completion

Table 3: All drill results reported greater than or equal to 0.1 g/t AuEq

*See gold equivalent (AuEq) formula in the ABOUT THE COPALQUIN SILVER GOLD PROJECT section

COPALQUIN - TARGET 1 UPGRADED MRE

(For full detail of the Target 1 MRE Upgrade see ASX announcement 3 July 2026 – “Amended Announcement Copalquin Project Target 1 Deposit MRE”)

The MRE for Target 1 ( Table 4 ) was generated as a base case assuming bulk underground mining method (long hole open stoping - LHOS) with mining widths averaging approximately 4 metres.  The MSO work identified areas where more selective underground mining methods such as cut and fill (higher cost than LHOS) could be utilised to reduce dilution and increase mined grades.   Table 5  provides the highlighted base case for undiluted mineralisation reporting within the underground mining shapes (mine stope optimiser – MSO ) at a cut-off grade of 1.5 g/t AuEq plus sensitivities to gold prices.

The difference between the undiluted grade of 6.85 g/t AuEq ( Table 5 Indicated base case) and the diluted grade of 4.26 g/ t AuEq ( Table 4 , Total Indicated Target 1 MRE) reflects this conservative mining dilution assumption whereby lower grade mineralisation surrounding the high-grade core would be extracted within geometry of a minable shape adding more tonnes and ounces at a lower average grade.   More detailed mining study work will fully assess the mining methods across the Target 1 MRE.

Table 4  Upgraded Copalquin Target 1 Mineral Resource Estimate (underground mining shape constrained & diluted)

Notes to Table 4 :

1. Numbers may not add due to rounding.  

2. All dollar values in United States Dollars (USD) unless otherwise noted.  

3. Mineral resources were prepared in accordance with the CIM Definition Standards (2014) and Estimation of Mineral Resource and Mineral Reserve Best Practice guidelines (2019), which are materially identical to the JORC Code (2012).  

4. The preparation of the mineral resource estimate was supervised by John Sims, President of Sims Resources LLC, an independent contractor and Qualified Person (QP), and Competent Person (CP), as a Certified Professional Geologist (CPG) member with the American Institute of Professional Geologists (AIPG).  

5. The effective date of the estimate is June 29, 2026.  

6. Inferred Mineral Resources have been estimated from geological evidence and drill core sampling and have a lower level of confidence than Measured and Indicated Mineral Resources due to the distance between sampled drill holes. Mineral resources are not mineral reserves and do not have demonstrated economic viability.  

7. Constrained and diluted Mineral Resources for Copalquin Target 1 are based on underlying metal prices of $3,300/oz Au and $50/oz Ag, unless otherwise noted.  

8. AuEq g/t = Au g/t + (Ag g/t x (Ag price/Au price) x (Ag recovery/Au recovery)), and is calculated using the underlying metals prices, along with metallurgical recoveries of 96% Au and 91% Ag from metallurgical test work on Target 1 composite samples. 11  

9. Underground Resource estimates are based on economically constrained mining shapes generated using Datamine’s Mineable Shape Optimizer (MSO) algorithm and the following optimization parameters:  

   • Diluted to a minimum 2 m shape width with a 92% mining recovery.  

   • Metallurgical recoveries of 96% for Au and 91% for Ag, from metallurgical test work on Target 1 composite samples. Longhole Open Stope mining with a total Mining+Processing+General and Administration (GA) cost of $97/t processed operating cost comprised of $60/t incremental mining, $25/t processing, $10/t GA, and $2/t sustaining.  

   • The mineable shapes reported are valued greater than the incremental cost to mine, which equates to approximately 1.0 g/t AuEq on a fully diluted basis.  

10. Mineral resources may be materially affected by environmental, permitting, legal, title, taxation, sociopolitical, marketing, or other relevant issues.  

11. In the Company’s opinion there is reasonable potential for both gold and silver to be extracted and sold.  

Table 5   Gold price sensitivity to constraining shapes, reported at 1.5 g/t AuEq cut-off (constrained and undiluted )

Notes to Table 5 :

1. The Table presents the results of a sensitivity analysis by varying gold prices on AuEq block model values and reports an undiluted tonnage, grade and metal content contained within the mining shapes.  The scenarios as presented are not considered to be a statement of mineral resources or reserves, and do not have demonstrated economic viability.  

2. AuEq calculated using metal prices of USD $3,300/oz Au and $50/oz Ag where AuEq g/t = Au g/t + (Ag g/t x (Ag price/Au price) x (Ag recovery/Au recovery)) with metallurgical recoveries of 96% Au and 91% Ag from metallurgical test work on Target 1 composite samples  An AuEq cut-off grade of 1.5 g/t was selected after applying 95% mining recovery and 5% dilution factors to the metal price and metallurgical recovery values.  

-ENDS-

Released with the authority of the Board.

For further information contact:

The Australian Securities Exchange has not reviewed and does not accept responsibility for the accuracy or adequacy of this release.

Neither TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Competent Persons Statement (JORC), and Qualified Persons (NI 43-101) Statement

The information in this announcement that relates to metallurgical test results, mineral processing and project development and study work has been compiled, reviewed and approved by Mr John Skeet who is Mithril’s CEO and Managing Director. Mr Skeet is a Fellow of the Australasian Institute of Mining and Metallurgy. This is a Recognised Professional Organisation (RPO) under the Joint Ore Reserves Committee (JORC) Code and Acceptable Foreign Association under NI 43-101.

Mr Skeet has sufficient experience of relevance to the styles of mineralisation and the types of deposits under consideration, and to the activities undertaken, to qualify as a Competent Person (non-independent) as defined in the 2012 Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, and as a Qualified Person (non-independent) as defined by NI 43-101. Mr Skeet consents to the inclusion in this report of the matters based on information in the form and context in which it appears. The Australian Securities Exchange has not reviewed and does not accept responsibility for the accuracy or adequacy of this release.

The information in this announcement that relates to sampling techniques, sample data, exploration results and geological interpretation for Mithril’s Mexican project, has been compiled, reviewed and approved by Mr James Barr who is Mithril’s Vice President - Exploration. Mr Barr is a registered member and Professional Geologist (P.Geo.) of the Engineers and Geoscientists of British Columbia. This is a Recognised Professional Organisation (RPO) under the Joint Ore Reserves Committee (JORC) Code and recognized Canadian Professional Association under NI 43-101.

Mr Barr has sufficient experience of relevance to the styles of mineralisation and the types of deposits under consideration, and to the activities undertaken, to qualify as a Competent Person (non-independent) as defined in the 2012 Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, and as a Qualified Person (non-independent) as defined by NI 43-101. Mr Barr consents to the inclusion in this report of the matters based on information in the form and context in which it appears.

The information in this announcement that relates to Mineral Resources has been compiled, reviewed and approved by Mr John Sims, a Certified Registered Geologist (CPG) with the American Institute of Professional Geologists (AIPG).  This is a Recognised Professional Organisation (RPO) under the Joint Ore Reserves Committee (JORC) Code and Acceptable Foreign Association under NI 43-101.

Mr Sims is acting as the Competent Person (independent), as defined in the 2012 Edition of the Joint Ore Reserves Committee (JORC) Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves, and as the Qualified Person (independent) as defined by NI 43-101, for the reporting of the Upgraded Copalquin Target 1 Mineral Resource Estimate, with effective date of June 29, 2026. A site visit was carried out by Mr Sims, between 5 May 2025 and 7 May 2025 to observe the drilling, logging, sampling and assay database. Mr Sims has reviewed and approved the contents of this report, and consents to the inclusion in this report of the matters based on information in the form and context in which it appears.

The relevant sections of “JORC Code, 2012 Edition - Table 1” as defined by the Joint Ore Reserves Committee (JORC) Code are incorporated into the Public Report announced as an amended version on ASX dated 3 July 2026 - Amended Announcement Copalquin Project Target 1 Deposit MRE.

A NI 43-101 Technical Report entitled “Technical Report and Upgraded Mineral Resource Estimate for the Copalquin Target 1 Area, Durango, Mexico” will be filed on SEDAR+ within 45 days of the release.

Qualified Persons – NI 43-101

Scientific and technical information in this Report has been reviewed and approved by Mr John Skeet (FAUSIMM, CP) Mithril’s Managing Director and Chief Executive Officer. Mr John Skeet is a qualified person within the meaning of NI 43-101.

Samples are sent to ALS Global with sample preparation performed in Chihuahua City, Mexico and assaying of sample pulps performed in North Vancouver, BC, Canada.

JORC Code, 2012 Edition – Table 1  

Section 1 Sampling Techniques and Data

Section 2 Reporting of Exploration Results