Description
An issue was discovered in OpenDKIM through 2.10.3, and 2.11.x through 2.11.0-Beta2. It fails to keep track of ordinal numbers when removing fake Authentication-Results header fields, which allows a remote attacker to craft an e-mail message with a fake sender address such that programs that rely on Authentication-Results from OpenDKIM will treat the message as having a valid DKIM signature when in fact it has none.
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 | opendkim | 2.11.0~beta2-9 | — |
| Debian 13 | opendkim | 2.11.0~beta2-9 | — |
| Debian 12 | opendkim | 2.11.0~beta2-8+deb12u1 | — |
| Debian 10 | opendkim | 2.11.0~alpha-12+deb10u1 | DLA-3680-1 |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | opendkim | No fix yet | — |
| Ubuntu 26.04 LTS | opendkim | No fix yet | — |
| Ubuntu 25.10 | opendkim | No fix yet | — |
| Ubuntu 24.04 LTS | opendkim | No fix yet | — |
| Ubuntu 22.04 LTS | opendkim | No fix yet | — |
Show 3 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 20.04 LTS | opendkim | No fix yet | — |
| Ubuntu 18.04 LTS | opendkim | No fix yet | — |
| Ubuntu 16.04 LTS | opendkim | No fix yet | — |
Advisories 1
- DLA-3680-1 opendkim - security update Debian Security (DSA / DLA) · Mar 9, 2026