CVE-2026-100891: Trusted Domain Project OpenDMARC Internationalized Domain Name opendmarc_policy.c opendmarc_policy_query_dmarc encoding error
A vulnerability has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this issue is the function opendmarcpolicyquerydmarc in the library libopendmarc/opendmarcpolicy.c of the component Internationalized Domain Name Handler. Such manipulation leads to encoding error. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
Affected Software
Event History
Frequently Asked Questions
Which deployments should be prioritized for triage?
OpenDMARC deployments running version 1.4.2 or earlier should be prioritized, particularly where the Internationalized Domain Name handling path is in use. The affected code is in libopendmarc/opendmarc_policy.c.
Does exploitation require authentication or user interaction?
No. The supplied CVSS vector indicates network-based exploitation with low attack complexity, no privileges required, and no user interaction required.
How likely is exploitation in the near term?
A public exploit has been disclosed and may be used. This should increase the priority of identifying exposed affected versions.