Mozilla blocked compromised intermediate eMudhra certificates via OneCRL on the 17th of October which was distributed to clients via RemoteSettings the same day. This update contains the updated OneCRL block list, ensuring clients will block the compromised certificates even if RemoteSettings is disabled by policy or otherwise unavailable in the user's network environment. This vulnerability was fixed in Firefox 158.0.1, Firefox ESR 153.5.1, Firefox ESR 115.43.1, Thunderbird 158.0.1, and Thunderbird 153.5.1.
Attack Parameters
Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Privileges Required
None
No privileges needed
User Interaction
Required
User action required
Impact Assessment
Confidentiality
Low
Partial data leak
Integrity
Low
Partial data modification
Availability
None
No disruption
CVSS Vector v3.1
Weakness Type (CWE)
Vulnerable Products
mozilla:firefox
References 7
https://bugzilla.mozilla.org/show_bug.cgi?id=2083382
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-111/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-112/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-113/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-114/
security@mozilla.org
https://www.mozilla.org/security/advisories/mfsa2026-115/
security@mozilla.org
http://www.openwall.com/lists/oss-security/2026/10/20/30
af854a3a-2127-422b-91ae-364da2661108