CVE-2026-95210: Critical severity GNU GnuTLS vulnerability
GnuTLS v3.8.13 does not reject a critical keyUsage extension when it cannot be processed, such as when extnValue is an ASN.1 NULL (05 00) instead of a BIT STRING. NOTE: the Supplier does not consider this an actionable security vulnerability because of its "threat model doesn't consider attacks only possible by modifying anything within the trust boundary (private keys, trusted certificate authorities and their issued certificates including intermediate CAs, etc.)" policy.
Other sources
Improper certificate validation in gnutls v3.8.13 causes the application to accept certificates containing invalid extensions.
— Microsoft
Affected Software
Event History
Frequently Asked Questions
Is the affected version range known?
The available information explicitly identifies GNU GnuTLS version 3.8.13. It does not provide an affected version range or a fixed version.