| Name | CVE-2026-107708 |
| Description | 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. |
| Source | CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more) |
| Debian Bugs | 1150461 |
Vulnerable and fixed packages
The table below lists information on source packages.
| Source Package | Release | Version | Status |
|---|
| krb5 (PTS) | bookworm, bookworm (security) | 1.20.1-2+deb12u5 | vulnerable |
| trixie (security), trixie | 1.21.3-5+deb13u1 | vulnerable |
| forky, sid | 1.22.1-3 | vulnerable |
The information below is based on the following data on fixed versions.
| Package | Type | Release | Fixed Version | Urgency | Origin | Debian Bugs |
|---|
| krb5 | source | (unstable) | (unfixed) | | | 1150461 |
Notes
[trixie] - krb5 <no-dsa> (Minor issue)
[bookworm] - krb5 <postponed> (Minor issue)
https://github.com/krb5/krb5/pull/1510
Fixed by: https://github.com/krb5/krb5/commit/f6e2c397ceda6467ebbaab8ed66d4895c9f1d6a7 (master)
Fixed by: https://github.com/krb5/krb5/commit/a88a18cafa1040a0c4f9c8d08288fc98831ec86d (krb5-1.22 branch)