CVE-2026-104038

Sssd: sssd: denial of service via missing sid extension in certificate mapping

Published Oct 6, 2026 CVSS 3.1 · 5.9 Medium EPSS < 1% KEV · Not listed
Description
A flaw was found in sssd. A remote attacker can cause a denial of service (DoS) by submitting a certificate that lacks an expected Security Identifier (SID) extension. In deployments configured with SID-based certificate mapping rules, the service fails to verify the presence of the extension before processing it, causing the process to crash during authentication or lookup operations.

Remediation

Vendor Workaround

A configuration-based workaround is available. Until a fix is shipped, avoid SSSD certificate mapping rules whose LDAPU1 maprule expands the {sid} or {sid.rid} templates (for example, 'maprule = LDAPU1:(objectsid={sid.rid})'). If SID-based mapping is required, reject certificates that lack the Microsoft SID extension (OID 1.3.6.1.4.1.311.25.2) before they reach the affected certificate mapping evaluation path, so SID-based rules fail cleanly instead of crashing the service.

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
First Time appeared Redhat rhel Els
CPEs cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
cpe:/a:redhat:enterprise_linux:10
cpe:/a:redhat:enterprise_linux:8
cpe:/a:redhat:enterprise_linux:9
cpe:/a:redhat:openshift:5
cpe:/o:redhat:rhel_els:6
cpe:/o:redhat:rhel_els:7
Vendors & Products Redhat rhel Els
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Redhat openshift Container Platform
Sssd
Sssd sssd
Vendors & Products Redhat openshift Container Platform
Sssd
Sssd sssd
Type Values Removed Values Added
Description A flaw was found in sssd. A remote attacker can cause a denial of service (DoS) by submitting a certificate that lacks an expected Security Identifier (SID) extension. In deployments configured with SID-based certificate mapping rules, the service fails to verify the presence of the extension before processing it, causing the process to crash during authentication or lookup operations.
Title Sssd: sssd: denial of service via missing sid extension in certificate mapping
First Time appeared Redhat
Redhat enterprise Linux
Redhat openshift
Weaknesses CWE-476
CPEs cpe:/a:redhat:openshift:4
cpe:/o:redhat:enterprise_linux:10
cpe:/o:redhat:enterprise_linux:6
cpe:/o:redhat:enterprise_linux:7
cpe:/o:redhat:enterprise_linux:8
cpe:/o:redhat:enterprise_linux:9
Vendors & Products Redhat
Redhat enterprise Linux
Redhat openshift
References
Metrics cvssV3_1

{'score': 5.9, 'vector': 'CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
redhat
Published
Updated
Nov 5, 2026, 3:52 PM
Reserved
Oct 1, 2026, 5:22 PM
Status
Undergoing Analysis
Published
Oct 6, 2026, 1:16 AM
Modified
Nov 5, 2026, 4:17 PM
Severity
Moderate
Public date
Oct 5, 2026, 11:50 PM