Out-of-bounds Write Vulnerability in Trusted Domain Project OpenDKIM
CVE-2026-100888

6.9MEDIUM

Key Information:

Vendor

Trusted Domain Project

Status
Opendkim
Vendor
CVE Published:
27 September 2026

Badges

👾 Exploit Exists🟡 Public PoC

What is CVE-2026-100888?

A vulnerability has been located in the Trusted Domain Project's OpenDKIM versions up to 2.11.0, specifically in the function dkim_canon_selecthdrs, part of the DKIM Signature Header Selection component. This issue arises from a manipulation of arguments leading to potential out-of-bounds write conditions, creating an avenue for remote exploitation. The exploit has been publicly disclosed, raising concerns for users and systems relying on this software, particularly as there has been no response from the vendor following initial contact regarding the issue.

Affected Version(s)

OpenDKIM 2.0

OpenDKIM 2.1

OpenDKIM 2.2

Exploit Proof of Concept (PoC)

PoC code is written by security researchers to demonstrate the vulnerability can be exploited. PoC code is also a key component for weaponization which could lead to ransomware.

CVE-2026-100888 - Proof of Concept

References

https://vuldb.com/vuln/410837
vdb-entrytechnical-description
https://vuldb.com/vuln/410837/cti
signaturepermissions-required
https://vuldb.com/cve/CVE-2026-100888
third-party-advisory

CVSS V4

Score:
6.9
Severity:
MEDIUM
Confidentiality:
Low
Integrity:
Low
Availability:
Low
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 🟡

    Public PoC available

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

Credit

WeitongLi (VulDB User)
VulDB CNA Team
.