NULL pointer dereference in Mit Krb5
CVE-2026-107708
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.
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
Weakness classification (CWE)
References
- github.com/krb5/krb5/pull/1510 (issue-tracking, patch)
- github.com/krb5/krb5/commit/f6e2c397ceda6467ebbaab8ed66d4895c9f1d6a7 (patch)
- github.com/krb5/krb5/commit/a88a18cafa1040a0c4f9c8d08288fc98831ec86d (patch)
- github.com/krb5/krb5/blob/krb5-1.22.2-final/src/kdc/kdc_util.c (technical-description)
- github.com/krb5/krb5 (product)
- www.vulncheck.com/advisories/mit-krb5-through-1.22.2-kdc-null-pointer-dereferen… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-107708?
- CVE-2026-107708 is a medium-severity vulnerability in Mit Krb5, classified under NULL Pointer Dereference. CVSS score: 4.9/10. Published 2026-10-08.
- How severe is CVE-2026-107708?
- Medium severity. CVSS v3 base score is 4.9 out of 10.