# CVE-2026-104034: SSSD use-after-free in Kerberos Credential Manager responder

Source: https://junglewise.ai/threats/cve-2026-104034-a-flaw-was-found-in-sssd-a-use-after-free-vulnerability-exists  
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-2026-104034 · Severity: medium · CVSS 4.7 · Published 2026-10-06

SSSD is a system service that manages user authentication and credentials on Linux systems. A memory bug in its Kerberos Credential Manager component can be triggered by an authenticated local user with a valid Kerberos ticket, causing the service to crash and become unavailable. This only affects systems where optional KCM ticket renewal is explicitly enabled.

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-2026-104034 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104034 being exploited in the wild.

**How severe is CVE-2026-104034?** Medium severity, with a CVSS score of 4.7, published 6 October 2026.

**Which products and versions are affected?** Red Hat SSSD.

**Is there a fix for CVE-2026-104034?** 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-2026-104034 attacked?** It is attacked with local access, in a hosted service.

**Am I affected by CVE-2026-104034?** Check whether you run Red Hat 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

A use-after-free vulnerability exists in the KCM responder during Kerberos TGT renewal, where a deferred callback accesses memory that has already been freed. Exploitation requires local authenticated access with a renewable Kerberos ticket and relies on the non-default KCM renewal feature being configured. Successful exploitation crashes the KCM responder service, resulting in a localized denial of service without credential exposure or privilege escalation.

## Affected products

- Red Hat 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-2026-104034](https://access.redhat.com/security/cve/CVE-2026-104034)

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