Vulnerability · Published Oct 6, 2026 · Assigned by redhat
CVE-2026-104039Sssd: sssd: denial of service via stale connection state reuse in pam gssapi responder
Medium 4.7
In plain English
A medium-severity security flaw in Red Hat Enterprise Linux 10 from Red Hat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.1% (higher than 3% of all known vulnerabilities).
Official description
A flaw was found in SSSD. A local user can cause a denial of service (DoS) by disrupting system authentication services. When handling Generic Security Services Application Programming Interface (GSSAPI) authentication in the Pluggable Authentication Module (PAM) responder, cached connection state is freed upon completion without clearing the reference pointer. An attacker can exploit this by sending an additional request over the same connection, causing the service to access invalid memory and unexpectedly terminate.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | sssd | no fix listed | DEBIAN-CVE-2026-104039 |
| Debian:13 | sssd | no fix listed | DEBIAN-CVE-2026-104039 |
| Ubuntu:22.04:LTS | sssd | no fix listed | UBUNTU-CVE-2026-104039 |
| Ubuntu:24.04:LTS | sssd | no fix listed | UBUNTU-CVE-2026-104039 |
| Ubuntu:26.04:LTS | sssd | no fix listed | UBUNTU-CVE-2026-104039 |
| Ubuntu:26.10 | sssd | no fix listed | UBUNTU-CVE-2026-104039 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | see references |
| Red Hat | Red Hat Enterprise Linux 6 | see references |
| Red Hat | Red Hat Enterprise Linux 7 | see references |
| Red Hat | Red Hat Enterprise Linux 8 | see references |
| Red Hat | Red Hat Enterprise Linux 9 | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
| Red Hat | Red Hat OpenShift Container Platform 4 | see references |
| Red Hat | Red Hat OpenShift Container Platform 5 | see references |
Weakness: CWE-825 · Vector: CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:N/I:N/A:H
References
- https://access.redhat.com/security/cve/CVE-2026-104039 vdb-entry, x_refsource_REDHAT
- RHBZ#2478956 issue-tracking, x_refsource_REDHAT