# CVE-2026-12610: SSSD use-after-free in PAM responder during YubiKey authentication

Source: https://junglewise.ai/threats/cve-2026-12610-sssd-use-after-free-in-pam-responder-during-yubikey  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-06-30. Updated: 2026-06-30  
License: CC BY 4.0 with a link back

CVE-2026-12610 · Severity: medium · CVSS 6.4 · Published 2026-06-30

A vulnerability in the System Security Services Daemon (SSSD), a service that manages access to remote directories and authentication mechanisms, can cause the system's authentication component to crash when using a YubiKey or smartcard. This issue can be triggered by a local attacker to cause a denial of service, preventing users from logging in, or potentially to gain elevated privileges on the system. The flaw occurs during the authentication process when memory is incorrectly handled after a request is cancelled or completed.

Technologies: [Red Hat Enterprise Linux 10](https://junglewise.ai/threats/technologies/enterprise-linux-10), [Red Hat Enterprise Linux 8](https://junglewise.ai/threats/technologies/enterprise-linux-8), [Red Hat Enterprise Linux 9](https://junglewise.ai/threats/technologies/enterprise-linux-9), [SSSD Project SSSD](https://junglewise.ai/threats/technologies/sssd). Vendors: [Red Hat](https://junglewise.ai/threats/vendors/red-hat), [SSSD Project](https://junglewise.ai/threats/vendors/sssd-project).

## Quick answers

**Is CVE-2026-12610 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-12610 being exploited in the wild.

**How severe is CVE-2026-12610?** Medium severity, with a CVSS score of 6.4, published 30 June 2026.

**Which products and versions are affected?** Red Hat Enterprise Linux 10 affected; Red Hat Enterprise Linux 8 affected; Red Hat Enterprise Linux 9 affected.

**Is there a fix for CVE-2026-12610?** 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-2026-12610 attacked?** It is attacked with local access, in an operating system.

**Am I affected by CVE-2026-12610?** Check whether you run Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 8, Red Hat Enterprise Linux 9 or one of the others listed 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

A use-after-free vulnerability exists in the SSSD PAM responder within the 'sss_certmap_match_cert' function. The root cause is that the 'sss_certmap_ctx' structure is owned by the PAM request state; if a request is cancelled or completes while the asynchronous 'p11_child' process is still running, the context is freed. When the child process eventually returns, 'parse_p11_child_response' attempts to use the dangling pointer, which may have been overwritten by certificate label data (e.g., "X.509 Certificate for PIV Authentication"). A local attacker with the ability to manipulate smartcard or YubiKey contents can trigger a crash (Denial of Service) or potentially influence memory to achieve privilege escalation.

## Affected products

- Red Hat Enterprise Linux 10 affected
- Red Hat Enterprise Linux 8 affected
- Red Hat Enterprise Linux 9 affected
- SSSD sssd

## Timeline

- 2026-06-09: other: Issue reported on SSSD GitHub repository
- 2026-06-18: other: Bug reported to Red Hat Bugzilla
- 2026-06-30: disclosed: CVE published

## References

- [https://access.redhat.com/downloads/content/package-browser/](https://access.redhat.com/downloads/content/package-browser/)
- [https://access.redhat.com/security/cve/CVE-2026-12610](https://access.redhat.com/security/cve/CVE-2026-12610)
- [https://bugzilla.redhat.com/show_bug.cgi?id=2490288](https://bugzilla.redhat.com/show_bug.cgi?id=2490288)
- [https://github.com/SSSD/sssd/issues/8796](https://github.com/SSSD/sssd/issues/8796)

## Related threats

- [SSSD PAM responder NULL pointer dereference](https://junglewise.ai/threats/cve-2026-127101-a-flaw-was-found-in-sssd-s-pam-responder-a-local-attacker-can)
- [sssd responder denial of service via file descriptor exhaustion](https://junglewise.ai/threats/cve-2026-88252-a-flaw-was-found-in-sssd-a-local-user-can-cause-a-denial-of)
- [SSSD NFS idmap plugin out-of-bounds write](https://junglewise.ai/threats/cve-2026-104036-a-flaw-was-found-in-sssd-s-nfs-idmap-plugin-when-retrieving)
- [SSSD Kerberos Credential Manager memory exhaustion denial of service](https://junglewise.ai/threats/cve-2026-104035-a-flaw-was-found-in-sssd-an-issue-in-the-kerberos-credential)
- [SSSD LDAP shadow expiration bypass](https://junglewise.ai/threats/cve-2026-104033-a-flaw-was-found-in-sssd-when-configured-to-enforce-account)