Mozilla Revokes Firefox and Thunderbird Linux Signing Key After Key Lands in Private Repo
Mozilla revoked the Firefox and Thunderbird Linux RPM signing subkey after an unencrypted copy landed in a private repo; no unauthorized access found.
Mozilla revoked the OpenPGP signing subkey (fingerprint 09BE ED63 F346 2A2D FFAB 3B87 5ECB 6497 C1A2 0256) used for Firefox and Thunderbird Linux downloads after an unencrypted copy was committed to one of its private repositories, citing reason code 2, 'key material has been compromised.' Audit records showed no sign of unauthorized access, and a replacement subkey (827E 6586 0867 9618 CD34 9F93 678E 455D 7676 7AA3) valid until August 5, 2028 was published. Users who verify signatures manually or install from Mozilla RPM packages may need to import the new key and remove the old one. The rotation came roughly seven months ahead of Mozilla's usual two-year subkey cycle.
Mozilla security advisory (AV26-868)
Canada's Cyber Centre reports Mozilla vulnerabilities fixed in Firefox 155 and Firefox ESR 115.40, 140.15, and 153.2.
Canadian Centre for Cyber Security advisory AV26-868, dated September 1, 2026, notes vulnerabilities in Firefox (versions prior to 155) and Firefox ESR (prior to 115.40, 140.15, and 153.2). The bulletin links to Mozilla's security advisories and urges users and administrators to update. No CVE identifiers or exploitation details are provided.
Mozilla security advisory (AV26-924)
Canadian Cyber Centre advisory AV26-924 lists vulnerabilities in Firefox 156 and Firefox ESR 115.41, 140.16, and 153.3, urging users to update.
The Canadian Centre for Cyber Security issued advisory AV26-924 on September 15, 2026, covering vulnerabilities in Firefox versions prior to 156 and Firefox ESR versions prior to 115.41, 140.16, and 153.3. Users and administrators are encouraged to review Mozilla's security advisories and apply updates. No exploitation details are included in the advisory.