# CVE-2026-127100: SSSD PAM responder NULL pointer dereference in JSON extension

Source: https://junglewise.ai/threats/cve-2026-127100-a-flaw-was-found-in-sssd-s-pam-responder-on-builds-with-the-json  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-11-12. Updated: 2026-11-12  
License: CC BY 4.0 with a link back

CVE-2026-127100 · Severity: medium · CVSS 5.5 · Published 2026-11-12

A flaw in SSSD's PAM responder authentication module causes it to crash when processing maliciously crafted login requests on systems with the JSON PAM extension enabled. A local attacker can trigger this denial of service to disrupt authentication for users relying on SSSD, preventing them from logging in until the service is manually restarted.

Technologies: [Red Hat SSSD](https://junglewise.ai/threats/technologies/red-hat-sssd). Vendors: [Red Hat](https://junglewise.ai/threats/vendors/red-hat).

## Quick answers

**Is CVE-2026-127100 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-127100 being exploited in the wild.

**How severe is CVE-2026-127100?** Medium severity, with a CVSS score of 5.5, published 12 November 2026.

**Which products and versions are affected?** Red Hat SSSD Affected in RHEL 9.8+ and RHEL 10.2+.

**Is there a fix for CVE-2026-127100?** 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-2026-127100 attacked?** It is attacked with local access, in a hosted service.

**Am I affected by CVE-2026-127100?** Check whether you run Red Hat SSSD at an affected version. 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

The vulnerability is a NULL pointer dereference (CWE-476) in SSSD's PAM responder when the JSON PAM extension is enabled. An attacker with local access can send a crafted authentication request with a non-string OAuth2 code value, bypassing JSON type validation and causing the PAM responder process to crash. This results in denial of service of SSSD-backed authentication with no confidentiality or integrity impact.

## Affected products

- Red Hat SSSD Affected in RHEL 9.8+ and RHEL 10.2+

## Timeline

- 2026-11-12: 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-2026-127100](https://access.redhat.com/security/cve/CVE-2026-127100)

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