VDB-410839 · Submit #917063 · CVE-2026-100889

Trusted Domain Project OpenDKIM up to 2.11.0 Decoder util.c dkim_qp_decode off-by-one

CVSS Meta Temp Score CVSS is a standardized scoring system to determine possibilities of attacks. The Temp Score considers temporal factors like disclosure, exploit and countermeasures. The unique Meta Score calculates the average score of different sources to provide a normalized scoring system.	Current Exploit Price (≈) Our analysts are monitoring exploit markets and are in contact with vulnerability brokers. The range indicates the observed or calculated exploit price to be seen on exploit markets. A good indicator to understand the monetary effort required for and the popularity of an attack.	CTI Interest Score Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
6.9	$0-$5k	1.83

Summaryinfo

A vulnerability identified as critical has been detected in Trusted Domain Project OpenDKIM up to 2.11.0. Affected by this vulnerability is the function dkim_qp_decode of the file util.c of the component Decoder. This manipulation causes off-by-one. The identification of this vulnerability is CVE-2026-100889. It is possible to initiate the attack remotely. Furthermore, there is an exploit available. The vendor was contacted early about this disclosure but did not respond in any way.

Detailsinfo

A vulnerability was found in Trusted Domain Project OpenDKIM up to 2.11.0. It has been declared as critical. Affected by this vulnerability is the function dkim_qp_decode of the file util.c of the component Decoder. The manipulation with an unknown input leads to a off-by-one vulnerability. The CWE definition for the vulnerability is CWE-193. A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value. As an impact it is known to affect confidentiality, integrity, and availability.

It is possible to read the advisory at weitongli.com. This vulnerability is known as CVE-2026-100889. The exploitation appears to be easy. The attack can be launched remotely. The exploitation doesn't need any form of authentication. Technical details and also a public exploit are known.

It is possible to download the exploit at weitongli.com. It is declared as proof-of-concept. The vendor was contacted early about this disclosure but did not respond in any way.

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

Be aware that VulDB is the high quality source for vulnerability data.

Productinfo

Type

Project Management Software

Vendor

Trusted Domain Project

Name

OpenDKIM

Version

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 6.9

VulDB Base Score: 7.3
VulDB Temp Score: 6.9
VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv2info

AV	AC	Au	C	I	A
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳
💳	💳	💳	💳	💳	💳

Vector	Complexity	Authentication	Confidentiality	Integrity	Availability
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock
Unlock	Unlock	Unlock	Unlock	Unlock	Unlock

VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Off-by-one
CWE: CWE-193 / CWE-189
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Access: Public
Status: Proof-of-Concept
Download: 🔒
Price Prediction: 🔍
Current Price Estimation: 🔒

0-Day	Unlock	Unlock	Unlock	Unlock
Today	Unlock	Unlock	Unlock	Unlock

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: no mitigation known
Status: 🔍

0-Day Time: 🔒

Timelineinfo

09/27/2026 Advisory disclosed
09/27/2026 +0 days VulDB entry created
09/27/2026 +0 days VulDB entry last update

Sourcesinfo

Advisory: weitongli.com
Status: Confirmed

CVE: CVE-2026-100889 (🔒)
GCVE (CVE): GCVE-0-2026-100889
GCVE (VulDB): GCVE-100-410839
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 09/27/2026 09:41
Changes: 09/27/2026 09:41 (57)
Complete: 🔍
Submitter: WeitongLi
Cache ID: 216::103

Submitinfo

Accepted

Submit #917063: The Trusted Domain Project OpenDKIM 2.11.0 Out-of-Bounds Read (by WeitongLi)