Fortuna acquires highly prospective Bambadji Project in Senegal from Barrick and IAMGOLD

NEWS RELEASE

Fortuna acquires highly prospective Bambadji Project in Senegal from Barrick and IAMGOLD

Vancouver, British Columbia, August 10, 2026: Fortuna Mining Corp. (NYSE: FSM | TSX: FVI) is pleased to announce the acquisition of the 190 km² Bambadji advanced gold exploration project in Senegal, through the purchase of certain Senegalese subsidiaries held by Barrick Mining Corporation and IAMGOLD Corporation. Located adjacent to Fortuna’s feasibility-stage Diamba Sud Gold Project, Bambadji consolidates approximately 60 kilometers of prospective strike along the Senegal-Mali Shear Zone, a Tier-1 gold corridor hosting several world-class mines.

Jorge A. Ganoza, President and CEO, commented, “Bambadji represents a rare opportunity to consolidate a large-scale, highly prospective exploration land package immediately adjacent to our feasibility-stage Diamba Sud Gold Project.” Mr. Ganoza continued, “The US$200 million consideration paid for the project reflects multiple prime drill-defined targets, the scale of the land package, the extensive historical exploration dataset, and the potential to materially expand Diamba Sud in one of the most prospective gold districts in West Africa, where quality ground is difficult to assemble.”

Barrick/IAMGOLD drill highlights include:

Fatima FARC001 2.44 g/t Au over a width of 24.0 meters from 52.0 meters FARC012 3.12 g/t Au over a width of 24.0 meters from 113.0 meters

Wari WARC004 4.05 g/t Au over a width of 9.0 meters from 28.0 meters BARC-2063 1.60 g/t Au over a width of 20.0 meters from 0.0 meters

Kach KCRC007 4.08 g/t Au over a width of 12.0 meters from 48.0 meters KCRC008 15.22 g/t Au over a width of 7.0 meters from 29.0 meters

Kabetea

Bagata Corridor BARC-2105 9.28 g/t Au over a width of 18.0 meters from 66.0 meters BARC-2159 3.57 g/t Au over a width of 46.0 meters from 56.0 meters

Note: All drill intervals are reported as downhole intervals. Mineralized structures/hosts are generally steep dipping between 70 to 85 degrees. Refer to Appendix 1 for full details of Barrick/IAMGOLD reverse circulation and diamond drill holes and assay results.

Bambadji Project Location

The Bambadji Project is contiguous with the eastern margin of Fortuna’s Diamba Sud Gold Project (refer to Figure 1), which hosts Mineral Reserves containing 1.15 million ounces of gold with a final investment decision anticipated shortly. Bambadji comprises two properties covering approximately 190 km² and extending over approximately 60 kilometers of prospective strike, with established secondary roads providing direct access from Diamba Sud.

Figure 1: Property Location Map

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Geology and Mineralization

The acquisition includes an extensive, high-quality exploration dataset comprising geochemical, geophysical, and lithological information, together with approximately 214,000 meters of historical auger, reverse circulation, and diamond drilling.

Historic drilling and fieldwork have identified several styles of gold mineralization across Bambadji, including analogues to the Diamba Sud breccia-style mineralization, Yalea sericite-albitite style, and the high-tourmaline Gara style. Across the project, at least eight significant drill-defined prospects have been identified, together with several highly prospective mineralized trends that remain open along strike and at depth. Historical drilling has generally been shallow and widely spaced, with several multikilometer gaps along these anomalous gold trends, providing clear targets for Fortuna’s initial exploration program.

2026 Exploration Program

Fortuna has approved an initial US$8 million exploration budget for Bambadji for the remainder of 2026, comprising 51,000 meters of reverse circulation and diamond drilling. Drilling is expected to commence in the third quarter.

The program is designed to improve confidence and definition across several advanced drill-defined targets located within a 20-kilometer radius of the proposed Diamba Sud plant site (refer to Figure 1). Eight priority targets have been identified for initial drilling, while generative exploration will continue in parallel to advance additional targets along the project’s highly prospective mineralized trends.

Transaction Terms

Pursuant to the terms of the definitive transaction agreements dated August 10, 2026 entered into between Fortuna and certain subsidiaries of Barrick and IAMGOLD (collectively, the “Sellers”), in consideration of the acquisition of the Bambadji Project, Fortuna paid US$200 million in cash from its treasury (US$130.35 million to a subsidiary of Barrick, and US$69.65 million to a subsidiary of IAMGOLD).

In addition, Fortuna has granted to the Sellers, a 0.5 percent net smelter return royalty on the first 1.75 million ounces of gold produced from the Bambadji Nord property (0.325 percent to a subsidiary of Barrick, and 0.175 percent to a subsidiary of IAMGOLD.

TD Securities acted as sole financial advisor to Fortuna with respect of the acquisition.

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Quality Assurance & Quality Control (QA - QC)

The drill database extends back to 1993 with IAMGOLD, Anmercosa Exploration (a subsidiary of Anglo American Ltd), Ashanti Goldfields and Barrick (formerly Randgold) variously managing exploration across that period. The majority of drilling has been conducted since 2007 by Barrick (Randgold). Industry standard practices were used throughout, reflecting the protocols of the day, however, not all can be verified.

Reverse circulation (RC) drilling used a 5.25-inch face sampling pneumatic hammer with samples collected into 60-liter plastic bags. Samples were kept dry by maintaining enough air pressure to exclude groundwater inflow. Once collected, RC samples were riffle split through a three-tier splitter to yield a 12.5 percent representative sample for submission to the analytical laboratory. The residual 87.5 percent samples were stored at the drill site until assay results were received and validated. Coarse reject samples for all mineralized samples corresponding to significant intervals were retained and stored on-site at the company-controlled core yard, however not all samples have been retained due to age degradation.

Diamond drilling (DD) drill holes generally started with HQ sized diameter, before reducing to NQ diameter diamond drill bits on intersecting fresh rock. The core was logged, marked up for sampling using standard lengths of one meter or to a geological boundary. Samples were then cut into equal halves using a diamond saw. One-half of the core was left in the original core box and stored in a secure location at the company core yard at the project site. The other half was sampled, catalogued, and placed into sealed bags and securely stored at the site until shipment.

Since 2016, RC and DD samples were transported by company vehicle or commercial courier to SGS Laboratories in Mali (Bamako) or ALS Kedougou/Ouagadougou. Routine gold analysis using a 50gram charge and fire assay with an atomic absorption finish was completed for all samples. Quality control procedures are noted as including the systematic insertion of blanks, duplicates and sample standards into the sample stream. In addition, the SGS laboratories insert their own quality control samples.

Qualified Person

Paul Weedon, Senior Vice President, Exploration for Fortuna Mining Corp., is a Qualified Person as defined by National Instrument 43-101 being a member of the Australian Institute of Geoscientists (Membership #6001). Mr. Weedon has reviewed and approved the scientific and technical information contained in this news release. Mr. Weedon has verified the data disclosed including sampling, analytical, and test data underlying the information or opinions contained herein by reviewing the methodologies described for sampling and analytical testing, assessing the results of QA – QC programs, validating the geochemical and geological databases and reviewing diamond drill core. The verification process identified that QA – QC data supporting some of the earlier historical drill results is more limited in nature with additional validation work including reassaying of samples and drilling of twin holes to be planned in future work programs for confirmation purposes.

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About Fortuna Mining Corp.

Fortuna Mining Corp. is a Canadian precious metals mining company with three operating mines and a portfolio of exploration projects in Argentina, Côte d’Ivoire, Guinea, Guyana, and Peru, as well as the Diamba Sud Gold Project in Senegal. Sustainability is at the core of our operations and stakeholder relationships. We produce gold and silver while creating long-term shared value through efficient production, environmental stewardship, and social responsibility. For more information, please visit our website at www.fortunamining.com

ON BEHALF OF THE BOARD

Jorge A. Ganoza

President, CEO, and Director Fortuna Mining Corp.

Investor Relations:

Carlos Baca | [email protected] | fortunamining.com | X | LinkedIn | YouTube | Instagram | TikTok

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Forward looking Statements

This news release contains forward-looking statements which constitute “forward-looking information” within the meaning of applicable Canadian securities legislation and “forward-looking statements” within the meaning of the “safe harbor” provisions of the Private Securities Litigation Reform Act of 1995 (collectively, “Forward-looking Statements”). All statements included herein, other than statements of historical fact, are Forward-looking Statements and are subject to a variety of known and unknown risks and uncertainties which could cause actual events or results to differ materially from those reflected in the Forward-looking Statements. The Forward-looking Statements in this news release include, without limitation, statements regarding the anticipated benefits of the Acquisition; timing of the final investment decision of Fortuna’s Diamba Sud Gold Project; the 2026 exploration program for Bambadji; the Mineral Resource estimates at Diamba Sud; the Company’s proposed exploration plans and timelines at Diamba Sud; potential for future resource growth at Diamba Sud; the Company’s business strategies, plans and outlook; the Company’s plans for its mines and mineral properties; and the future financial or operating performance of the Company. Often, but not always, these Forward-looking Statements can be identified by the use of words such as “estimated”, “potential”, “open”, “future”, “assumed”, “projected”, “proposed”, “used”, “detailed”, “has been”, “gain”, “planned”, “reflecting”, “will”, “anticipated”, “estimated”, “containing”, “remaining”, “to be”, or statements that events, “could” or “should” occur or be achieved and similar expressions, including negative variations.

Forward-looking Statements involve known and unknown risks, uncertainties and other factors which may cause the actual results, performance, or achievements of the Company to be materially different from any results, performance or achievements expressed or implied by the Forward-looking Statements. Such uncertainties and factors include, among others, operational risks associated with mining and mineral processing; uncertainty relating to Mineral Resource and Mineral Reserve estimates; uncertainty relating to capital and operating costs, production schedules and economic returns; risks relating to the Company’s ability to replace its Mineral Reserves; risks related to the conversion of Mineral Resources to Mineral Reserves; risks associated with mineral exploration and project development; uncertainty relating to the repatriation of funds as a result of currency controls; environmental matters including obtaining or renewing environmental permits and potential liability claims; uncertainty relating to nature and climate conditions; laws and regulations regarding the protection of the environment (including greenhouse gas emission reduction and other decarbonization requirements and the uncertainty surrounding the interpretation of omnibus Bill C-59 and the related amendments to the Competition Act (Canada); risks associated with political instability and changes to the regulations governing the Company’s business operations; changes in national and local government legislation, taxation, controls, regulations and political or economic developments in countries in which the Company does or may carry on business; risks associated with war, hostilities or other conflicts, such as the Ukrainian – Russian, Israeli – Hamas and Iran – Israel and United States conflicts, and the impacts they may have on global economic activity; risks relating to the termination of the Company’s mining concessions in certain circumstances; developing and maintaining relationships with local communities and stakeholders; risks associated with losing control of public perception as a result of social media and other web-based applications; potential opposition to the Company’s exploration, development and operational activities; risks related to the Company’s ability to obtain adequate financing for planned exploration and development activities; property title matters; risks related to the ability to retain or extend title to the Company’s mineral properties; risks relating to the integration of businesses and assets acquired by the Company; impairments; risks associated with climate change legislation; reliance on key personnel; adequacy of insurance coverage; operational safety and security risks; legal proceedings and potential legal proceedings; uncertainties relating to

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general economic conditions; risks relating to a global pandemic, which could impact the Company’s business, operations, financial condition and share price; competition; fluctuations in metal prices; risks associated with entering into commodity forward and option contracts for base metals production; fluctuations in currency exchange rates and interest rates; tax audits and reassessments; risks related to hedging; uncertainty relating to concentrate treatment charges and transportation costs; sufficiency of monies allotted by the Company for land reclamation; risks associated with dependence upon information technology systems, which are subject to disruption, damage, failure and risks with implementation and integration; labor relations issues; as well as those factors discussed under “Risk Factors” in the Company's Annual Information Form for the fiscal year ended December 31, 2025. Although the Company has attempted to identify important factors that could cause actual actions, events, or results to differ materially from those described in Forward-looking Statements, there may be other factors that cause actions, events or results to differ from those anticipated, estimated or intended.

Forward-looking Statements contained herein are based on the assumptions, beliefs, expectations and opinions of management, including, but not limited to, the accuracy of the Company’s current Mineral Resource and Mineral Reserve estimates; that the Company’s activities will be conducted in accordance with the Company’s public statements and stated goals; that there will be no material adverse change affecting the Company, its properties or its production estimates (which assume accuracy of projected ore grade, mining rates, recovery timing, and recovery rate estimates and may be impacted by unscheduled maintenance, labor and contractor availability and other operating or technical difficulties); the duration and effect of global and local inflation; the duration and impacts of geo-political uncertainties on the Company’s production, workforce, business, operations and financial condition; the expected trends in mineral prices, inflation and currency exchange rates; that all required approvals and permits will be obtained for the Company’s business and operations on acceptable terms; that there will be no significant disruptions affecting the Company's operations and such other assumptions as set out herein. Forward-looking Statements are made as of the date hereof and the Company disclaims any obligation to update any Forward-looking Statements, whether as a result of new information, future events, or results or otherwise, except as required by law. There can be no assurance that these Forward-looking Statements will prove to be accurate, as actual results and future events could differ materially from those anticipated in such statements. Accordingly, investors should not place undue reliance on Forward-looking Statements.

Cautionary Note to United States Investors Concerning Mineral Resources and Mineral Reserves Technical disclosure regarding the Company’s properties included herein has been prepared in accordance with National Instrument 43-101, Standards of Disclosure for Mineral Projects ("NI 43- 101") and the Canadian Institute of Mining, Metallurgy, and Petroleum Definition Standards on Mineral Resources and Mineral Reserves. Canadian standards, including NI 43-101, differ from the requirements of the Securities and Exchange Commission, and information included herein may not be comparable to similar information disclosed by U.S. companies.

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Appendix 1: Bambadji Project historic drill program details of the drill holes and assay results of significance

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