Use-after-free in SSSD KCM ticket renewal causes denial of service
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- High
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Deferred Red Hat: fix deferred
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
SSSD in Red Hat Enterprise Linux 6, 7, 8, 9 and 10 and Red Hat OpenShift Container Platform 4 and 5 has a use-after-free flaw (CWE-825). A deferred callback in the Kerberos Credential Manager (KCM) responder accesses memory that was already released during ticket-granting ticket renewal. An authenticated local user with a renewable Kerberos ticket can trigger it on systems configured with KCM renewal, crashing the KCM responder service and causing a denial of service.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Description from the CNA
A flaw was found in SSSD. A use-after-free vulnerability exists in the Kerberos Credential Manager (KCM) responder during Kerberos ticket-granting ticket (TGT) renewal, where a deferred callback accesses memory that has already been released. An authenticated local user with a renewable Kerberos ticket can trigger this issue on systems configured with KCM renewal, causing the KCM responder service to crash and resulting in a Denial of Service (DoS).
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Red Hat | Red Hat Enterprise Linux 10 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 6 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 7 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 8 | — | — | No fix listed | CNA |
| Red Hat | Red Hat Enterprise Linux 9 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 4 | — | — | No fix listed | CNA |
| Red Hat | Red Hat OpenShift Container Platform 5 | — | — | No fix listed | CNA |
- Red Hat Enterprise Linux 10 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 6 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 7 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 8 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat Enterprise Linux 9 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 4 VendorRed Hat Affected — Fixed in — No fix listed CNA
- Red Hat OpenShift Container Platform 5 VendorRed Hat Affected — Fixed in — No fix listed CNA
CPE names CNA · 7
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:/a:redhat:enterprise_linux:10 | 10 | — | Red Hat |
| cpe:/o:redhat:rhel_els:6 | 6 | — | Red Hat |
| cpe:/o:redhat:rhel_els:7 | 7 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:8 | 8 | — | Red Hat |
| cpe:/a:redhat:enterprise_linux:9 | 9 | — | Red Hat |
| cpe:/a:redhat:openshift:4 | 4 | — | Red Hat |
| cpe:/a:redhat:openshift:5 | 5 | — | Red Hat |
- cpe:/a:redhat:enterprise_linux:10 Versions 10 — ·Red Hat
- cpe:/o:redhat:rhel_els:6 Versions 6 — ·Red Hat
- cpe:/o:redhat:rhel_els:7 Versions 7 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:8 Versions 8 — ·Red Hat
- cpe:/a:redhat:enterprise_linux:9 Versions 9 — ·Red Hat
- cpe:/a:redhat:openshift:4 Versions 4 — ·Red Hat
- cpe:/a:redhat:openshift:5 Versions 5 — ·Red Hat
Remediation
The sources list no fixed version for Red Hat Enterprise Linux 6, 7, 8, 9 and 10. The sources list no fixed version for Red Hat OpenShift Container Platform 4 and 5. Red Hat lists no fix planned for Red Hat Enterprise Linux 6 and no plan available for the other listed products.
Written with Claude Haiku 5.5 from the sources below · 2026-11-06
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 10 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 4 | Affected | No fix yet: Fix deferred |
| Red Hat OpenShift Container Platform 5 | Affected | No fix yet: Fix deferred |
Timeline
- 2026-10-06 Threatist record created from CVE-2026-104034
- 2026-10-06 Alias added: GHSA-fcpm-98rx-c93x
- 2026-10-06 Affected versions changed · Red Hat
- 2026-10-06 CVSS score added · Red Hat
- 2026-10-06 CISA SSVC decision points changed
- 2026-11-05 Affected versions changed · CNA
- 2026-11-05 Affected versions changed · Red Hat
References
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Sources
- CVE-2026-104034 · CVE Program
- CVE-2026-104034 · NVD
- FIRST EPSS
- GHSA-fcpm-98rx-c93x · GitHub Advisory Database · CC BY 4.0
- CVE-2026-104034 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences