Description
In MIT Kerberos 5 (aka krb5) before 1.22.3, there is an integer underflow and resultant out-of-bounds read if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, possibly causing the process to terminate in parse_message.
Affected products
mit: kerberos 5
References3
- web.mit.edu/kerberos/advisories/ Vendor Advisory
- cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabil… ExploitThird Party AdvisoryPatch
- github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a13… Patch
Metrics
- CVSS 3.1
-
7.5
HIGH
Score source: NVD
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H - EPSS — exploit probability
- 1% percentile: 49 · as of 13 November 2026
- CWE
- CWE-191
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