CVE-2026-40356
7.5
HIGH
CVSS 3.1
EPSS 0.50%
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.
How to fix CVE-2026-40356
To remediate CVE-2026-40356, upgrade the affected package to a fixed version below.
- —upgrade to 1.18.3-6+deb11u8 or later
Is CVE-2026-40356 being exploited?
Low — EPSS is 0.5%, meaning exploitation activity has not been observed at scale.
Affected packages (1)
- from 0, < 1.18.3-6+deb11u8
CVSS scores
| Source | Version | Severity | Vector |
|---|---|---|---|
| osv | CVSS 3.1 | HIGH7.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |