---
id: CVE-2026-100889
title: A vulnerability was detected in Trusted Domain Project OpenDKIM up to 2.11.0
summary: >-
  A vulnerability was detected in Trusted Domain Project OpenDKIM up to 2.11.0.
  Affected is the function dkim_qp_decode of the file util.c of the component
  Decoder. The manipulation results in off-by-one. The attack may be performed
  from r…
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-189
  - CWE-193
vendor: Trusted Domain Project
product: OpenDKIM
affected:
  - OpenDKIM 2.0
  - OpenDKIM 2.1
  - OpenDKIM 2.2
  - OpenDKIM 2.3
  - OpenDKIM 2.4
  - OpenDKIM 2.5
  - OpenDKIM 2.6
  - OpenDKIM 2.7
  - OpenDKIM 2.8
  - OpenDKIM 2.9
  - OpenDKIM 2.10
  - OpenDKIM 2.11.0
published: '2026-09-28'
updated: '2026-09-28'
sourceUpdated: '2026-09-28T15:16:04.793'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-100889'
references:
  - url: 'https://vuldb.com/cve/CVE-2026-100889'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/submit/917063'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/vuln/410839'
    label: cna@vuldb.com
  - url: 'https://vuldb.com/vuln/410839/cti'
    label: cna@vuldb.com
  - url: 'https://weitongli.com/share/opendkim-qp-off-by-one.html'
    label: cna@vuldb.com
  - url: >-
      https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-100889.json
  - url: 'https://access.redhat.com/security/cve/CVE-2026-100889'
  - url: 'https://www.cve.org/CVERecord?id=CVE-2026-100889'
tags:
  - nvd
  - cve.org
  - csaf
  - vex
  - red-hat
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-28T13:06:30.451887Z'
scores:
  nvd: 7.3
  vendor: 7.5
  cna: 7.3
ingestedAt: '2026-09-27T23:59:58.080Z'
epss: 0.003
epssPercentile: 0.22553
---

## Overview

A vulnerability was detected in Trusted Domain Project OpenDKIM up to 2.11.0. Affected is the function dkim_qp_decode of the file util.c of the component Decoder. The manipulation results in off-by-one. The attack may be performed from remote. The exploit is now 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.

## Vendor advisories

- **Red Hat VEX** · updated 2026-09-28 · [vex](https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-100889.json)