# CVE-2026-104042: sssd PAM responder denial of service via out-of-bounds read

Source: https://junglewise.ai/threats/cve-2026-104042-a-flaw-was-found-in-sssd-a-local-attacker-can-cause-a-denial-of  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-06. Updated: 2026-10-06  
License: CC BY 4.0 with a link back

CVE-2026-104042 · Severity: medium · CVSS 5.5 · Published 2026-10-06

sssd is a system service that handles user authentication and authorization on Linux systems. A local attacker can crash the PAM responder component by sending a specially crafted authentication request with a zero-length token, disrupting authentication services until the service is manually restarted.

Technologies: [Sssd](https://junglewise.ai/threats/technologies/x-sssd).

## Quick answers

**Is CVE-2026-104042 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104042 being exploited in the wild.

**How severe is CVE-2026-104042?** Medium severity, with a CVSS score of 5.5, published 6 October 2026.

**Which products and versions are affected?** sssd.

**Is there a fix for CVE-2026-104042?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-104042 attacked?** It is attacked with local access.

**Am I affected by CVE-2026-104042?** Check whether you run Sssd. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

Out-of-bounds read vulnerability (CWE-125) in sssd's PAM responder caused by missing input validation on authentication tokens. A local attacker with low privileges can send a zero-length authentication token to the responder socket, causing the service to read beyond buffer boundaries and crash. No privilege escalation or data exposure occurs; impact is limited to denial of service.

## Affected products

- sssd

## Timeline

- 2026-10-06: disclosed

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-104042](https://access.redhat.com/security/cve/CVE-2026-104042)

## Related threats

- [SSSD memory exhaustion in IdP authentication pre-requests](https://junglewise.ai/threats/cve-2026-104046-a-flaw-was-found-in-sssd-system-security-services-daemon-when)
- [sssd denial of service via passkey Kerberos authentication](https://junglewise.ai/threats/cve-2026-104044-a-flaw-was-found-in-sssd-a-local-attacker-can-trigger-a-denial)
- [SSSD use-after-free in PAM GSSAPI responder](https://junglewise.ai/threats/cve-2026-104039-a-flaw-was-found-in-sssd-a-local-user-can-cause-a-denial-of)