Description
In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| MIT | Kerberos 5 | 1.18 – < 1.22.3 | 1.22.3 |
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 | 1.22.1-2.1 | — |
| Debian 13 | krb5 | 1.21.3-5+deb13u1 | — |
| Debian 12 | krb5 | 1.20.1-2+deb12u5 | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.04 LTS | krb5 | 1.22.1-2ubuntu4.1 | USN-8585-1 |
| Ubuntu 25.10 | krb5 | No fix yet | — |
| Ubuntu 24.04 LTS | krb5 | 1.20.1-6ubuntu2.7 | USN-8585-1 |
| Ubuntu 22.04 LTS | krb5 | 1.19.2-2ubuntu0.8 | USN-8585-1 |
Red Hat
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| RHEL 10 | krb5 +8 | 1.21.3-10.el10_2 | RHSA-2026:19145 |
| RHEL 9 | krb5 +8 | 1.21.1-10.el9_8 | RHSA-2026:19357 |
| RHEL 8 | krb5 +7 | 1.18.2-34.el8_10 | RHSA-2026:16799 |
Show 1 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Red Hat Hardened Images 1 | krb5 +8 | 1.22.2-7.hum1 | RHSA-2026:12220 |
AlmaLinux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| AlmaLinux 10 | libkadm5 +7 | 1.21.3-10.el10_2 | ALSA-2026:19145 |
| AlmaLinux 9 | libkadm5 +7 | 1.21.1-10.el9_8 | ALSA-2026:19357 |
| AlmaLinux 8 | libkadm5 +6 | 1.18.2-34.el8_10 | ALSA-2026:16799 |
Rocky Linux
Errata ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Rocky Linux 10 | krb5 | 1.21.3-10.el10_2 | RLSA-2026:19145 |
| Rocky Linux 9 | krb5 | 1.21.1-10.el9_8 | RLSA-2026:97456, RLSA-2026:19357 |
| Rocky Linux 8 | krb5 | 1.18.2-34.el8_10 | RLSA-2026:16799 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | krb5 | 1.20.1-150600.11.19.1 | SUSE-SU-2026:2848-1 |
| SLES 15 SP6 | krb5 | 1.20.1-150600.11.19.1 | SUSE-SU-2026:2848-1 |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 16.0 | krb5 | 1.21.3-160000.3.1 | SUSE-SU-2026:22322-1 |
| SLES for SAP 15 SP6 | krb5 | 1.20.1-150600.11.19.1 | SUSE-SU-2026:2848-1 |
| SLES 16.0 | krb5 | 1.21.3-160000.3.1 | SUSE-SU-2026:22322-1 |
| SLE Micro 6.2 | krb5 | 1.21.3-160000.3.1 | SUSE-SU-2026:22255-1 |
| SLE Micro 5.4 | krb5 | 1.19.2-150400.3.21.1 | SUSE-SU-2026:2449-1 |
| SLE Micro 5.3 | krb5 | 1.19.2-150400.3.21.1 | SUSE-SU-2026:2449-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | krb5 | 1.22.2-3.1 | openSUSE-SU-2026:10729-1 |
| openSUSE Leap 16.0 | krb5 | 1.21.3-160000.3.1 | openSUSE-SU-2026:21021-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | krb5 | 1.22.3-r0 | — |
| Alpine v3.23 | krb5 | 1.22.3-r0 | — |
Amazon Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Amazon Linux 2023 | libkadm5 +6 | 1.21.3-7.amzn2023.0.1 | ALAS2023-2026-1680 |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | krb5 | 1.21.3-4 | — |
Oracle Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Oracle Linux 10 | libkadm5 +7 | 1.21.3-10.0.1.el10_2 | ELSA-2026-19145 |
| Oracle Linux 9 | libkadm5 +7 | 1.21.1-10.0.1.el9_8 | ELSA-2026-19357 |
| Oracle Linux 8 | libkadm5 +6 | 1.18.2-34.0.1.el8_10 | ELSA-2026-16799 |
Advisories 29
- WID-SEC-2026-4435 MIT Kerberos: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 12, 2026
- RLSA-2026:97456 Moderate: krb5 security update Rocky Linux Security Advisories · Nov 11, 2026
- WID-SEC-2026-1290 MIT Kerberos: Mehrere Schwachstellen ermöglichen Denial of Service BSI CERT-Bund (WID) · Nov 10, 2026
- SSA-457936 SSA-457936: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.7 Siemens ProductCERT · Nov 10, 2026
- ALSA-2026:19357 Important: krb5 security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:19145 Important: krb5 security update AlmaLinux Security Advisories · Oct 29, 2026
- ALSA-2026:16799 Important: krb5 security update AlmaLinux Security Advisories · Oct 29, 2026
- ICSA-26-295-11 Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP CISA ICS & IT advisories · Oct 22, 2026
- RHSA-2026:19357 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:19145 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:16799 Red Hat Security Advisory: krb5 security update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- RHSA-2026:12220 Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update Red Hat Security Advisories (RHSA) · Oct 15, 2026
- SSA-019113 SSA-019113: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.6 Siemens ProductCERT · Oct 13, 2026
- SSA-082556 SSA-082556: Vulnerabilities in the additional GNU/Linux subsystem of the SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP V3.1.5 Siemens ProductCERT · Oct 13, 2026
- ICSA-26-209-04 Siemens SIMATIC S7-1500 CPU 1518(F)-4 PN/DP MFP CISA ICS & IT advisories · Jul 28, 2026
- USN-8585-1 krb5 vulnerabilities Ubuntu Security Notices (USN) · Jul 22, 2026
- ELSA-2026-19145 Important: krb5 security update (Oracle Linux 10) Oracle Linux Security Advisories (ELSA) · Jul 16, 2026
- SUSE-SU-2026:2848-1 Security update for krb5, krb5-mini SUSE / openSUSE Security Updates · Jul 11, 2026
- SUSE-SU-2026:22322-1 Security update for krb5 SUSE / openSUSE Security Updates · Jul 2, 2026
- openSUSE-SU-2026:21021-1 Security update for krb5 SUSE / openSUSE Security Updates · Jun 30, 2026
- SUSE-SU-2026:22255-1 Security update for krb5 SUSE / openSUSE Security Updates · Jun 30, 2026
- ELSA-2026-19357 Important: krb5 security update (Oracle Linux 9) Oracle Linux Security Advisories (ELSA) · Jun 23, 2026
- SUSE-SU-2026:2449-1 Security update for krb5 SUSE / openSUSE Security Updates · Jun 19, 2026
- RLSA-2026:19145 Important: krb5 security update Rocky Linux Security Advisories · May 29, 2026
- RLSA-2026:19357 Important: krb5 security update Rocky Linux Security Advisories · May 28, 2026
- RLSA-2026:16799 Important: krb5 security update Rocky Linux Security Advisories · May 14, 2026
- ALAS2023-2026-1680 Moderate: krb5 security update (Amazon Linux 2023) Amazon Linux Security Center (ALAS) · May 13, 2026
- ELSA-2026-16799 Important: krb5 security update (Oracle Linux 8) Oracle Linux Security Advisories (ELSA) · May 13, 2026
- openSUSE-SU-2026:10729-1 krb5-1.22.2-3.1 on GA media SUSE / openSUSE Security Updates · May 9, 2026