Reference page — cumulative record through Saturday, October 3, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.
CVE-2026-100891
Trusted Domain Project OpenDMARC Internationalized Domain Name opendmarc_policy.c opendmarc_policy_query_dmarc encoding error
AV AC AT PR UI VC VI VA CVSS EPSS %ile KEV
N L N N N L L L 5.5 .0029 19.9 —
AFFECTED
Product Versions Fixed
OpenDMARC 1.4.0 – —
TIMELINE
Sep 27 Reserved by VulDB
Sep 28 EXPLOIT PUBLISHED — CVE-2026-100891 (Trusted Domain Project OpenDMARC). Public exploit reference added.
Sep 28 Published (CNA: VulDB)
Oct 1 EXPLOIT PUBLISHED — CVE-2026-100891 (Trusted Domain Project OpenDMARC). Public exploit reference added.
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.
Lifecycle
Complete event history — 4 events, chronological
| Date | Event | Detail |
|---|
| September 27, 2026 | Reserved | Reserved by VulDB |
| September 28, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-100891 (Trusted Domain Project OpenDMARC). Public exploit reference added. |
| September 28, 2026 | Published | Published (CNA: VulDB) |
| October 1, 2026 | EXPLOIT PUBLISHED | EXPLOIT PUBLISHED — CVE-2026-100891 (Trusted Domain Project OpenDMARC). Public exploit reference added. |
Affected
Affected products and packages — 1 row
| Vendor | Product / Package | Ecosystem | Version introduced | Fixed |
|---|
| Trusted Domain Project | OpenDMARC | — | 1.4.0 | — |
About this page
This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-100891 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Saturday, October 3, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.
