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.
Fix
Patch, vendor advisory and mitigation references on NVD 3
- https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html Exploit, Third Party Advisory, Patch
- https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f Patch
- https://web.mit.edu/kerberos/advisories/ Vendor Advisory
Every line above is quoted from NVD, CISA, Microsoft, the vendor's own advisory or DISA; nothing is generated.
Change history 1
- First seenCVSS 7.5 · mitNVD modified 2026-10-26 22:10
Affected (CPE criteria) 1
cpe:2.3:a:mit:kerberos_5:*:*:*:*:*:*:*:*
References 3
- https://cems.fun/2026/04/27/krb5-two-unauthenticated-network-vulnerabilities.html Exploit, Third Party Advisory, Patch
- https://github.com/krb5/krb5/commit/2e75f0d9362fb979f5fc92829431a590a130929f Patch
- https://web.mit.edu/kerberos/advisories/ Vendor Advisory