CVE-2026-104038
Sssd: sssd: denial of service via missing sid extension in certificate mapping
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.
Fixes and workarounds
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.
Source: CNA: redhatAffected products and versions
| Product | Versions | Authority |
|---|---|---|
| Red Hat Enterprise Linux 10 Red Hat sssd
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 6 Red Hat sssd
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: unknown |
CNA: redhat |
| Red Hat Enterprise Linux 7 Red Hat sssd
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 8 Red Hat sssd
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat Enterprise Linux 9 Red Hat sssd
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Container Platform 4 Red Hat openshift/ose-rhel-coreos-8
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Container Platform 4 Red Hat openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
| Red Hat OpenShift Container Platform 5 Red Hat openshift/ose-rhel-coreos-9
https://access.redhat.com/downloads/content/package-browser/ |
Range not reported
Other versions: affected |
CNA: redhat |
Version ranges are source assertions. Check the vendor advisory and your installed configuration before determining exposure.
CVSS assessments
| Version / score | Vector | Authority |
|---|---|---|
| 3.1 / 5.9 medium |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H | CNA: redhat |
Exploit evidence
- https://bugzilla.redhat.com/show_bug.cgi?id=2478980
exploit · ADP: CISA-ADP
References
- https://access.redhat.com/security/cve/CVE-2026-104038CNA: redhat · vdb-entry, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2478980CNA: redhat · issue-tracking, x_refsource_REDHAT
- https://bugzilla.redhat.com/show_bug.cgi?id=2478980ADP: CISA-ADP · exploit
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