Vulnerability in Trusted Domain Project Opendmarc
CVE-2026-100891
A vulnerability has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this issue is the function opendmarc_policy_query_dmarc in the library libopendmarc/opendmarc_policy.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.
Published .
CVSS v3 metric
CVSS v3 base score 7.3 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L.
EPSS exploit prediction
No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.
Affected products
- Trusted Domain Project Opendmarc — versions 1.4.0, 1.4.1, 1.4.2
Weakness classification (CWE)
References
- vuldb.com/vuln/410841 (technical-description, vdb-entry)
- vuldb.com/vuln/410841/cti (signature, permissions-required)
- vuldb.com/cve/CVE-2026-100891 (third-party-advisory)
- vuldb.com/submit/917215 (third-party-advisory)
- weitongli.com/share/opendmarc-ulabel-not-converted.html (exploit)
Frequently asked questions
- What is CVE-2026-100891?
- CVE-2026-100891 is a high-severity vulnerability in Trusted Domain Project Opendmarc, classified under CWE-172. CVSS score: 7.3/10. Published 2026-09-28.
- How severe is CVE-2026-100891?
- High severity. CVSS v3 base score is 7.3 out of 10.