Log in Start free

Vulnerability · Published Sep 28, 2026 · Assigned by VulDB

CVE-2026-100891Trusted Domain Project OpenDMARC Internationalized Domain Name opendmarc_policy.c opendmarc_policy_query_dmarc encoding error

High 7.3

In plain English

A high-severity security flaw in OpenDMARC from Trusted Domain Project. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 22% of all known vulnerabilities).

Severity (CVSS 3.1)7.3High
Exploit odds (30 days)0.3%top 77.9% of all CVEs
Exploited in the wildNo reportsCISA SSVC: poc
Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12opendmarcno fix listedDEBIAN-CVE-2026-100891
Debian:13opendmarcno fix listedDEBIAN-CVE-2026-100891
Debian:14opendmarcno fix listedDEBIAN-CVE-2026-100891
Ubuntu:22.04:LTSopendmarcno fix listedUBUNTU-CVE-2026-100891
Ubuntu:24.04:LTSopendmarcno fix listedUBUNTU-CVE-2026-100891
Ubuntu:26.04:LTSopendmarcno fix listedUBUNTU-CVE-2026-100891
Ubuntu:26.10opendmarcno fix listedUBUNTU-CVE-2026-100891

Affected products (as reported)

VendorProductVersions
Trusted Domain Project OpenDMARC 1.4.01.4.11.4.2

Weakness: CWE-172 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L/E:P/RL:X/RC:C

References