Description
Heimdal is an implementation of ASN.1/DER, PKIX, and Kerberos. Versions prior to 7.7.1 are vulnerable to a denial of service vulnerability in Heimdal's PKI certificate validation library, affecting the KDC (via PKINIT) and kinit (via PKINIT), as well as any third-party applications using Heimdal's libhx509. Users should upgrade to Heimdal 7.7.1 or 7.8. There are no known workarounds for this issue.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| heimdal | heimdal | < 7.7.1 | — |
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 | heimdal | 7.8.git20221115.a6cf945+dfsg-1 | — |
| Debian 13 | heimdal | 7.8.git20221115.a6cf945+dfsg-1 | — |
| Debian 12 | heimdal | 7.8.git20221115.a6cf945+dfsg-1 | — |
| Debian 11 | heimdal | 7.7.0+dfsg-2+deb11u2 | DSA-5287-1 |
| Debian 10 | heimdal | 7.5.0+dfsg-3+deb10u1 | DLA-3206-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | heimdal | No fix yet | — |
| Ubuntu 26.04 LTS | heimdal | No fix yet | — |
| Ubuntu 25.10 | heimdal | No fix yet | — |
| Ubuntu 24.04 LTS | heimdal | No fix yet | — |
| Ubuntu 22.04 LTS | heimdal | No fix yet | — |
Show 4 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | heimdal | 7.7.0+dfsg-1ubuntu1.2 | USN-5766-1 |
| Ubuntu 18.04 LTS | heimdal | 7.5.0+dfsg-1ubuntu0.2 | USN-5766-1 |
| Ubuntu Pro 16.04 LTS | heimdal | 1.7~git20150920+dfsg-4ubuntu1.16.04.1+esm2 | USN-5766-1 |
| Ubuntu Pro 14.04 LTS | heimdal | 1.6~git20131207+dfsg-1ubuntu1.2+esm2 | USN-5766-1 |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SUSE Package Hub 15 SP4 | libheimdal | 7.8.0-bp154.2.4.1 | openSUSE-SU-2023:0019-1 |
| SUSE Package Hub 15 SP3 | libheimdal | 7.8.0-bp153.2.4.1 | openSUSE-SU-2023:0020-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Leap 15.4 | libheimdal | 7.8.0-bp154.2.4.1 | openSUSE-SU-2023:0019-1 |
| openSUSE Leap 15.3 | libheimdal | 7.8.0-bp153.2.4.1 | openSUSE-SU-2023:0020-1 |
Alpine
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.24 | heimdal | 7.7.1-r0 | — |
| Alpine v3.23 | heimdal | 7.7.1-r0 | — |
| Alpine v3.22 | heimdal | 7.7.1-r0 | — |
| Alpine v3.21 | heimdal | 7.7.1-r0 | — |
| Alpine v3.20 | heimdal | 7.7.1-r0 | — |
Show 6 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Alpine v3.19 | heimdal | 7.7.1-r0 | — |
| Alpine v3.18 | heimdal | 7.7.1-r0 | — |
| Alpine v3.17 | heimdal | 7.7.1-r0 | — |
| Alpine v3.16 | heimdal | 7.7.1-r0 | — |
| Alpine v3.15 | heimdal | 7.7.1-r0 | — |
| Alpine v3.14 | heimdal | 7.7.1-r0 | — |
Azure Linux
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Azure Linux 3 | samba | 4.18.3-1 | — |
| Azure Linux 2 (CBL-Mariner) | heimdal | 7.7.1-1 | — |
Advisories 7
- WID-SEC-2022-2057 Heimdal: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 28, 2026
- USN-5766-1 heimdal vulnerability Ubuntu Security Notices (USN) · Jun 29, 2026
- DSA-5287-1 heimdal - security update Debian Security (DSA / DLA) · Mar 9, 2026
- DLA-3206-1 heimdal - security update Debian Security (DSA / DLA) · Mar 9, 2026
- openSUSE-SU-2023:0019-1 Security update for libheimdal SUSE / openSUSE Security Updates · Feb 4, 2026
- openSUSE-SU-2023:0020-1 Security update for libheimdal SUSE / openSUSE Security Updates · Feb 4, 2026
- WID-SEC-2022-2372 genua genugate: Mehrere Schwachstellen BSI CERT-Bund (WID) · Jan 19, 2023