A flaw was found in SSSD. A use-after-free vulnerability exists in the Kerberos Credential Manager (KCM) responder during Kerberos ticket-granting… (CVE-2026-104034)
Description
A use-after-free vulnerability exists in the Kerberos Credential Manager (KCM) responder component of SSSD during Kerberos ticket-granting ticket renewal. An authenticated local user with a renewable Kerberos ticket can trigger this flaw on systems configured with KCM renewal, causing the KCM responder service to crash and resulting in a denial of service. The vulnerability affects multiple specific versions of SSSD. The CVSS score is 4.7, indicating a medium severity level.
CVSS v3.1
Score 4.7medium
Affected software
pkg:deb/ubuntu/sssd?arch=source&distro=esm-infra-legacy/xenialpkg:deb/ubuntu/sssd?arch=source&distro=esm-infra/bionicpkg:deb/ubuntu/sssd?arch=source&distro=esm-infra/focalpkg:deb/ubuntu/sssd?arch=source&distro=jammypkg:deb/ubuntu/sssd?arch=source&distro=noblepkg:deb/ubuntu/sssd?arch=source&distro=resoluteRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-104034 is a use-after-free vulnerability in the Kerberos Credential Manager (KCM) responder of SSSD. It occurs during the renewal of Kerberos ticket-granting tickets (TGT), where a deferred callback accesses memory that has already been freed. This flaw allows an authenticated local user with a renewable Kerberos ticket to cause the KCM responder service to crash, leading to a denial of service condition on affected systems configured with KCM renewal.
Potential Impact
The vulnerability results in a denial of service by crashing the KCM responder service. It requires an authenticated local user with a renewable Kerberos ticket to trigger the issue. There is no impact on confidentiality or integrity reported. The denial of service could disrupt Kerberos ticket renewal functionality on affected systems.
Mitigation Recommendations
No specific patch or remediation information is provided in the available data. Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, limiting local user access or disabling KCM renewal where feasible may reduce exposure.
Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- UBUNTU-CVE-2026-104034
- Osv Schema Version
- 1.7.0
- Ecosystems
- ["Ubuntu:Pro:16.04:LTS","Ubuntu:Pro:18.04:LTS","Ubuntu:Pro:20.04:LTS","Ubuntu:22.04:LTS","Ubuntu:24.04:LTS","Ubuntu:26.04:LTS"]
- Cvss Version
- 3.1
- State
- PUBLISHED
Threat ID: 6ac80fcc2cdf04f65639c4bf
Added to database: 10/08/2026, 21:49:00 UTC
Last enriched: 10/08/2026, 22:17:44 UTC
Last updated: 10/09/2026, 01:48:07 UTC
Views: 1
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