CVEvulnerability
CVE-2026-40356
7.5 HIGH
Official page ↗
- Status
- Analyzed
- Published
- 2026-04-28
- Last modified
- 2026-10-26
- Assigner
- [email protected]
- CVSS 3.1 ([email protected])
- 5.9 MEDIUM — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
- CVSS 3.1 ([email protected])
- 7.5 HIGH — CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- Weaknesses
- CWE-191
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 configurations
• mit kerberos 5 (>= 1.18.0 <= 1.22.2)
Related
Weakness · CWE (1)
- CWE-191 Integer Underflow (Wrap or Wraparound) weakness
References
- 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