Bug 2548262 (CVE-2026-107708) - CVE-2026-107708 krb5: krb5: Denial of Service via malformed PAC in S4U2Proxy requests
Summary: CVE-2026-107708 krb5: krb5: Denial of Service via malformed PAC in S4U2Proxy ...
Keywords:
Status: NEW
Alias: CVE-2026-107708
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
medium
medium
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-10-08 20:31 UTC by OSIDB Bzimport
Modified: 2026-10-12 04:34 UTC (History)
28 users (show)

Fixed In Version:
Clone Of:
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Description OSIDB Bzimport 2026-10-08 20:31:24 UTC 
MIT krb5 through 1.22.2 contains a NULL pointer dereference vulnerability in the KDC's get_pac_princ_with_realm() that returns success while leaving the client principal NULL on malformed names. A malicious or compromised cross-realm trusted KDC can send an S4U2Proxy request with a PAC carrying a malformed client name to crash krb5kdc and deny authentication.
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