Description
The pkinit_server_return_padata function in plugins/preauth/pkinit/pkinit_srv.c in the PKINIT implementation in the Key Distribution Center (KDC) in MIT Kerberos 5 (aka krb5) before 1.10.4 attempts to find an agility KDF identifier in inappropriate circumstances, which allows remote attackers to cause a denial of service (NULL pointer dereference and daemon crash) via a crafted Draft 9 request.
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | krb5 | 1.10.1+dfsg-4+nmu1 | — |
| Debian 13 | krb5 | 1.10.1+dfsg-4+nmu1 | — |
| Debian 12 | krb5 | 1.10.1+dfsg-4+nmu1 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 14.04 LTS | krb5 | 1.12+dfsg-2ubuntu4.2 | USN-2310-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 6 | krb5 +6 | 1.10.3-10.el6_4.1 | RHSA-2013:0656 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | krb5 | 1.15-1.1 | openSUSE-SU-2024:10004-1 |
Advisories 3
- RHSA-2013:0656 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Jun 26, 2026
- USN-2310-1 krb5 vulnerabilities Ubuntu Security Notices (USN) · Apr 22, 2026
- openSUSE-SU-2024:10004-1 krb5-1.15-1.1 on GA media SUSE / openSUSE Security Updates · Feb 4, 2026