CVE-2026-88647 GnuTLS - Authentication Bypass

GnuTLS 3.8.13 contains a hostname verification bypass caused by improper Common Name fallback mechanism handling, letting attackers eavesdrop on communications via crafted certificates, exploit requires crafted certificate.

CVSS base score 9.1 /10
Critical
CISA KEV
Not listed
Public exploit
None known
EPSS
0.21% chance of exploitation in 30 days
View the NVD record ↗

Details

Type
Authentication Bypass
Impact
Man In The Middle, Information Disclosure
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
Published
8 October 2026
Updated
15 October 2026
Weakness
CWE-297

Vendor fix

Update to the latest version of GnuTLS.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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