Medium [CVE-2026-90994] Sssd: sssd: denial of service via malformed pam v1 requests
This medium-severity Red Hat Linux advisory covers CVE-2026-90994 affecting Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 6, Red Hat Enterprise Linux 7.
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Summary
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. Red Hat severity: Moderate — CVSS 4 (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L).
Weakness: CWE-125. Affected Red Hat products: Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 6; Red Hat Enterprise Linux 7; Red Hat Enterprise Linux 8; Red Hat Enterprise Linux 9; Red Hat OpenShift Container Platform 4.
Will not fix / out of support: Red Hat Enterprise Linux 6. Red Hat does not currently list a fixing RHSA for this CVE.
Affected products named by the advisory: Red Hat package: libsss_autofs; Red Hat package: libsss_certmap; Red Hat package: libsss_nss_idmap-devel; Red Hat package: python3-libipa_hbac; and 27 more.
Affected products named by the advisory: Red Hat package: python3-libsss_nss_idmap; Red Hat package: python3-sss-murmur; Red Hat package: python3-sssdconfig; Red Hat package: sssd-ad; and 23 more.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
Fixed versions
No fixed release is recorded yet. That does not prove no patch exists — confirm against the vendor advisory.
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
Mitigation checklist
- Restrict local access to the PAM responder UNIX socket, typically located at `/var/lib/sss/pipes/pam`, to only trusted users and processes. This can be achieved by adjusting file system permissions on the socket file.
Official advisory · high-confidence parse· fetched 2 hours ago·verify at source
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