# CVE-2026-104036: SSSD NFS idmap plugin out-of-bounds write

Source: https://junglewise.ai/threats/cve-2026-104036-a-flaw-was-found-in-sssd-s-nfs-idmap-plugin-when-retrieving  
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-2026-104036 · Severity: medium · CVSS 5.8 · Published 2026-10-06

SSSD is a system service that manages user identity and authentication on Linux systems, including NFS file server access. A flaw in its NFS identity mapping plugin can crash the identity service when an authenticated local user requests lookups that resolve to oversized cached names, potentially corrupting system memory and causing service outages. Exploitation requires specific deployment with memcached lookups enabled.

Technologies: [SSSD Project SSSD](https://junglewise.ai/threats/technologies/sssd). Vendors: [SSSD Project](https://junglewise.ai/threats/vendors/sssd-project).

## Quick answers

**Is CVE-2026-104036 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-104036 being exploited in the wild.

**How severe is CVE-2026-104036?** Medium severity, with a CVSS score of 5.8, published 6 October 2026.

**Which products and versions are affected?** SSSD Project SSSD.

**Is there a fix for CVE-2026-104036?** 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-2026-104036 attacked?** It is attacked with local access, in a software library.

**Am I affected by CVE-2026-104036?** Check whether you run SSSD Project 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 write (CWE-787) in SSSD's NFS idmap plugin when processing cached user or group names exceeding destination buffer size. The plugin detects the overflow condition but fails to abort before copying data, allowing a local attacker with low privileges to trigger the vulnerability via identity resolution requests for oversized cached entries. This causes DoS through idmap daemon crash and potential memory corruption.

## Affected products

- SSSD Project 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-2026-104036](https://access.redhat.com/security/cve/CVE-2026-104036)

## 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 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)
- [SSSD memory leak in autofs responder](https://junglewise.ai/threats/cve-2026-104031-a-flaw-was-found-in-sssd-in-configurations-where-the-autofs)