---
id: CVE-2026-100891
title: A vulnerability has been found in Trusted Domain Project OpenDMARC up to 1.4.2
summary: >-
  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 …
severity: high
cvss: 7.3
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L'
cwe:
  - CWE-172
vendor: Trusted Domain Project
product: OpenDMARC
affected:
  - OpenDMARC 1.4.0
  - OpenDMARC 1.4.1
  - OpenDMARC 1.4.2
published: '2026-09-28'
updated: '2026-09-28'
sourceUpdated: '2026-09-28T01:16:28.367'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-100891'
references:
  - url: 'https://vuldb.com/cve/CVE-2026-100891'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/submit/917215'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/vuln/410841'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/vuln/410841/cti'
    label: cna@vuldb.com
  - url: 'https://weitongli.com/share/opendmarc-ulabel-not-converted.html'
    label: cna@vuldb.com
tags:
  - nvd
  - cve.org
ingestedAt: '2026-09-28T01:00:36.648Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.