CVE-2026-90994 Sssd: sssd: denial of service via malformed pam v1 requests
A local attacker can cause a denial of service in the SSSD PAM responder by sending malformed protocol v1 requests, affecting Red Hat Enterprise Linux systems.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-90994?
CVE-2026-90994 is a medium-severity denial of service vulnerability in Red Hat Enterprise Linux 10, published on 14 Sep 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, specifically within the PAM (Pluggable Authentication Modules) responder's protocol v1 parser, pam_parse_in_data(). A local client with access to the PAM responder's UNIX socket can exploit this by negotiating protocol v1 and sending an empty or truncated PAM request body. This can trigger an out-of-bounds read, potentially causing the PAM responder to terminate or restart, leading to a local denial of service.
Weakness: CWE-125
Which versions are affected by CVE-2026-90994?
How do I fix CVE-2026-90994?
Apply the vendor's patch.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2026-90994 being exploited?
There is no known exploitation of CVE-2026-90994 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2026-90994, GHSA-m9pj-qp75-2h63, UBUNTU-CVE-2026-90994.