Intimation of probable data breach incident

NO. GMDC/CS/NSE/BSE/028/2026 September 4, 2026 To, To, National Stock Exchange of India, Bombay Stock Exchange Ltd. Exchange Plaza, 25th Floor, P.J. Towers Bandra Kurla Complex Dalal Street Bandra (East) , Mumbai – 400 051 Fort, Mumbai-400 001 Code : GMDCLTD Code : 532181 Dear Sir / Madam, Subject : Disclosure under Regulation 30 of the SEBI (Listing Obligations and Disclosure Requirements) Regulations, 2015 – Intimation of Probable data breach Incident I am directed to inform that the Company has received an intimation from CERT-in that there may be a probable data breach pertaining to the Company at: https://www.gmdcltd.com, . Upon receiving such intimation, the Company immediately activated its verification and appropriate cyber security incident response and investigation mechanism. The Company has also engaged its internal and external cyber security experts to assess the nature, scope and impact of the probable data breach incident on the basis of the CERT-in Advisory We further state that the above probable breach has not affected our core operations and systems and they have remained fully functional throughout. You are requested to take the above disclosure on record. Thanking you, Yours faithfully, For Gujarat Mineral Development Corporation Limited Company Secretary Gujarat Mineral Development Corporation Limited (A Government of Gujarat Enterprise) CIN : L14100GJ1963SGC001206 “Khanij Bhavan”, 132 Ft. Ring Road, Near University Ground, Vastrapur, Ahmedabad-52 Phone : 27913200/3501 Email: cs.co@gmdcltd.com Website: www.gmdcltd.com