CVE-2026-104034

CVE-2026-104034 is a medium-severity vulnerability with a CVSS 3.x base score of 4.7. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-825.

Key facts

Description

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).

Frequently asked questions

What is CVE-2026-104034?
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).
How severe is CVE-2026-104034?
CVE-2026-104034 has a CVSS 3.x base score of 4.7, rated medium severity. It is exploitable over local access with high attack complexity, requires low privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability high.
Is CVE-2026-104034 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (1st percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2026-104034?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2026-104034 published?
CVE-2026-104034 was published on 2026-10-06.

References

Other CWE-825 vulnerabilities

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