CVE-2026-100889 Trusted Domain Project OpenDKIM Decoder util.c dkim_qp_decode off-by-one
Remote attackers can exploit an off-by-one error in OpenDKIM's decoder to potentially execute code or cause denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-100889?
CVE-2026-100889 is a medium-severity vulnerability in Trusted Domain Project OpenDKIM, published on 27 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A vulnerability was detected in Trusted Domain Project OpenDKIM up to 2.11.0. Affected is the function dkim_qp_decode of the file util.c of the component Decoder. The manipulation results in off-by-one. The attack may be performed from remote. The exploit is now public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Which versions are affected by CVE-2026-100889?
How do I fix CVE-2026-100889?
No fix has been published for CVE-2026-100889 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-100889 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100889 exists.
Sources
Also known as DEBIAN-CVE-2026-100889, GHSA-87hw-mmxf-r6m3, UBUNTU-CVE-2026-100889.