CVE-2026-107708: NULL Pointer Dereference in MIT krb5
Description
MIT krb5 versions up to 1.22.2 have a NULL pointer dereference vulnerability in the KDC component's get_pac_princ_with_realm() function. This flaw occurs when processing malformed client names in S4U2Proxy requests from a malicious or compromised cross-realm trusted KDC, potentially causing the krb5kdc service to crash and deny authentication.
CVSS v4.0
Score 6.9medium
Affected software
MIT
krb5
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AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
CVE-2026-107708 is a vulnerability in MIT krb5 through version 1.22.2 involving a NULL pointer dereference in the KDC's get_pac_princ_with_realm() function. When a cross-realm trusted KDC sends an S4U2Proxy request with a Privilege Attribute Certificate (PAC) containing a malformed client name, the function returns success but leaves the client principal NULL. This leads to a crash of the krb5kdc service, resulting in denial of authentication services.
Potential Impact
An attacker who controls or compromises a cross-realm trusted KDC can exploit this vulnerability to crash the krb5kdc service by sending specially crafted S4U2Proxy requests. This causes denial of authentication services, impacting availability. There is no indication of privilege escalation or data disclosure from the provided data.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, administrators should consider restricting or monitoring cross-realm trust relationships to potentially untrusted KDCs to reduce exposure.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-10-08T16:52:24.550Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6ac7feea2cdf04f656318bd8
Added to database: 10/08/2026, 20:36:58 UTC
Last enriched: 10/08/2026, 21:18:58 UTC
Last updated: 10/08/2026, 21:18:58 UTC
Views: 4
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