CVE-2026-104036 Sssd: sssd: denial of service via out-of-bounds write in nfs idmap plugin
A local attacker can cause a denial of service or potential code execution in SSSD's NFS idmap plugin via an out-of-bounds write during identity lookups.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-104036?
CVE-2026-104036 is a medium-severity memory corruption vulnerability in Red Hat Enterprise Linux 10, published on 6 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Official description
A flaw was found in SSSD's NFS idmap plugin. When retrieving cached user or group names, the plugin detects if an entry exceeds the destination buffer size but fails to abort before copying data. A local attacker can trigger this vulnerability by requesting identity lookups that resolve to oversized cached entries, resulting in an out-of-bounds write. This flaw primarily leads to a Denial of Service (DoS) by crashing the identity mapping service, and may also corrupt adjacent process memory.
Weakness: CWE-787
Which versions are affected by CVE-2026-104036?
How do I fix CVE-2026-104036?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-104036 being exploited?
There is no known exploitation of CVE-2026-104036 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-104036, GHSA-95ww-m774-j7x2, OESA-2026-4425, UBUNTU-CVE-2026-104036.