Public vulnerability disclosure

CVE-2026-90995

Sssd: sssd: local denial of service due to null pointer dereference in pam responder

publishedCWE-476

A flaw was found in SSSD (System Security Services Daemon). A local attacker with privileges to connect to the PAM (Pluggable Authentication Modules) responder socket can send a specially crafted protocol request. If the `pam_app_services` configuration is enabled and the service item is omitted from the request, a NULL pointer dereference can occur. This vulnerability leads to a denial of service, causing the PAM responder to crash and disrupt authentication services.

Technical severity5.5 mediumCVSS 3.1 · CNA: redhat
Published2026-09-14Source updated 2026-11-06
Collected2026-11-062 attributed sources

Fixes and workarounds

Workaround

To mitigate this issue, avoid configuring `pam_app_services` in the `[pam]` section of `/etc/sssd/sssd.conf` if it is not operationally required. If `pam_app_services` is configured, remove or comment out the `pam_app_services` line and restart the `sssd` service. Example: ``` # /etc/sssd/sssd.conf [pam] # pam_app_services = app_svc ``` After modifying the configuration, restart the SSSD service: `systemctl restart sssd` Note that restarting the SSSD service may temporarily interrupt authentication and authorization services.

Source: CNA: redhat

Affected products and versions

Affected products, source version ranges and reporting authorities
ProductVersionsAuthority
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

CVSS scores, vectors and reporting authorities
Version / scoreVectorAuthority
3.1 / 5.5
medium
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HCNA: redhat

Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

References

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