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.
Published: 2026-10-06
Score: 5.9 Medium
EPSS: n/a
KEV: No
AI Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Remediation

Vendor Workaround

To mitigate this issue, reconfigure SSSD certificate mapping rules to avoid using `{sid}` or `{sid.rid}` expansion templates within `LDAPU1` mapping rules. 1. Inspect `/etc/sssd/sssd.conf` and any configuration snippets in `/etc/sssd/conf.d/` for `maprule` directives that expand `{sid}` or `{sid.rid}`. 2. Modify the mapping rules to use alternative certificate attributes or ensure certificates without the Microsoft SID extension (OID 1.3.6.1.4.1.311.25.2) are rejected before reaching the certificate mapping evaluation. 3. Restart the SSSD service to apply the configuration changes: ``` systemctl restart sssd ``` Warning: Restarting the SSSD service temporarily interrupts identity lookup and authentication requests on the system. Modifying active certificate mapping rules may prevent certificate authentication for users whose accounts rely strictly on SID-based mapping.

Tracking

Sign in to view the affected projects.

Advisories

No advisories yet.

History

Tue, 06 Oct 2026 00:45:00 +0000

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'}


Subscriptions

Redhat Enterprise Linux Openshift
cve-icon MITRE

Status: PUBLISHED

Assigner: redhat

Published:

Updated: 2026-10-06T00:12:27.072Z

Reserved: 2026-10-01T17:22:59.849Z

Link: CVE-2026-104038

cve-icon Vulnrichment

No data.

cve-icon NVD

No data.

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses