# CVE-2026-90995: Sssd: sssd: local denial of service due to null pointer dereference in pam responder

Status: published. Published: 2026-09-14. Updated: 2026-11-06.

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.

## Remediation

- 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

- Red Hat / Red Hat Enterprise Linux 10 (sssd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 6 (sssd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 7 (sssd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 8 (sssd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat Enterprise Linux 9 (sssd): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-8): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 4 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat
- Red Hat / Red Hat OpenShift Container Platform 5 (openshift/ose-rhel-coreos-9): Version range not reported. Source: CNA: redhat

## Severity and prioritization

- CVSS 3.1: 5.5 (medium); CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H; source: CNA: redhat

- CISA KEV: No listing in collected sources

- EPSS: 0.14% as of 2026-11-05; percentile 3.03%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-476

## Exploit evidence

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

## References

- https://access.redhat.com/security/cve/CVE-2026-90995 (CNA: redhat; vdb-entry, x_refsource_REDHAT)

- https://bugzilla.redhat.com/show_bug.cgi?id=2479464 (CNA: redhat; issue-tracking, x_refsource_REDHAT)

## Provenance

- CNA: redhat: https://www.cve.org/CVERecord?id=CVE-2026-90995; retrieved 2026-11-06; source updated 2026-11-06

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-90995; retrieved 2026-11-06; source updated Not reported

Revision: 2b4c1310f4a9eb5a2ebeb1ab8b08dfc115e5f7a6aa5fa672ef0e72b03a6ace0e

Canonical: https://y2.dev/cve/CVE-2026-90995

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