CVE-2026-127101 · Infrastructure
NO FIX YET
SSSD's PAM responder dereferences a NULL protocol-version pointer when an authentication request arrives before the client protocol version is negotiated. A local attacker can crash the responder and, by repeating crafted requests, keep SSSD-backed authentication down.
first public Nov 12, 2026 · 1 source
Check it with your coding agent
It reads this page and tells you if your code or app is affected.
Systems on Linux that authenticate users through SSSD's PAM responder are exposed. The attacker needs local access to the machine to send the request, so hosts with no local user access carry lower risk. Systems that do not use SSSD for PAM authentication can skip it.
Not affected if no-local-access, no-sssd
Who cares linux, pam, self-hosted, sssd
sssd --version or rpm -q sssd / dpkg -l sssdsss in /etc/nsswitch.conf and pam_sss in /etc/pam.d/No fix yet, per the sources.
A flaw was found in SSSD's PAM responder. A local attacker can send an authentication request without first negotiating the client protocol version. The responder dereferences a NULL protocol-version pointer and crashes, disrupting SSSD-backed authentication. Repeated crafted requests can sustain the denial of service.
This page as .md · .json · CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
NVD data is provided by NIST and is public domain. Posts quoted belong to their authors.
Are you affected?
Ask from here. InfraStack checks the affected versions against your stack and answers in your inbox.
InfraStack checks the affected versions against your stack and answers in Slack, with the evidence and the fix.
InfraStack checks it against your stack and answers on your report, with the evidence and the fix.