Executive brief
sssd is a system service that provides user authentication and account management on Linux systems. A local unprivileged user can send a specially crafted request to crash or destabilize the NSS responder component, causing authentication services to become unavailable and impacting system availability.
Technical details
The vulnerability is an integer underflow (CWE-191) in sssd's Network Security Services (NSS) responder that processes incoming requests. A local unprivileged attacker can trigger a denial-of-service condition by sending a crafted request with a zero-length body to the NSS responder's local UNIX socket, causing the responder to become unstable or terminate. The attack requires local access and does not require elevated privileges or user interaction. The vulnerability affects only availability; there is no path to remote code execution or privilege escalation. No mitigation is currently available.
Affected products
- SSSD Project sssd <UNKNOWN>
Timeline
- 2026-09-14: disclosed
- 2026-09-14: advisory