CVE-2026-100890 Trusted Domain Project OpenDMARC SPF Parser opendmarc_spf.c opendmarc_spf_ipv6_explode null pointer dereference
Remote attackers can cause a denial of service in OpenDMARC via a null pointer dereference in the SPF parser, requiring attention from mail server administrators.
- 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-2026-100890?
CVE-2026-100890 is a medium-severity vulnerability in Trusted Domain Project OpenDMARC, published on 28 Sep 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
A flaw has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this vulnerability is the function opendmarc_spf_ipv6_explode in the library libopendmarc/opendmarc_spf.c of the component SPF Parser. This manipulation of the argument cp causes null pointer dereference. It is possible to initiate the attack remotely. The exploit has been published 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-2026-100890?
How do I fix CVE-2026-100890?
No fix has been published for CVE-2026-100890 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-100890 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-100890 exists.
Sources
Also known as DEBIAN-CVE-2026-100890, GHSA-98vv-3xrg-44wc, UBUNTU-CVE-2026-100890.