Trusted Domain Project OpenDMARC up to 1.4.2 Internationalized Domain Name opendmarc_policy.c opendmarc_policy_query_dmarc encoding error

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
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6.9$0-$5k1.05

Summaryinfo

A vulnerability marked as critical has been reported in Trusted Domain Project OpenDMARC up to 1.4.2. This affects the function opendmarc_policy_query_dmarc in the library libopendmarc/opendmarc_policy.c of the component Internationalized Domain Name Handler. Performing a manipulation results in encoding error. This vulnerability is identified as CVE-2026-100891. The attack can be initiated remotely. Additionally, an exploit exists. The vendor was contacted early about this disclosure but did not respond in any way.

Detailsinfo

A vulnerability classified as critical has been found in Trusted Domain Project OpenDMARC up to 1.4.2. This affects the function opendmarc_policy_query_dmarc in the library libopendmarc/opendmarc_policy.c of the component Internationalized Domain Name Handler. The manipulation with an unknown input leads to a encoding error vulnerability. CWE is classifying the issue as CWE-172. The product does not properly encode or decode the data, resulting in unexpected values. This is going to have an impact on confidentiality, integrity, and availability.

The advisory is shared at weitongli.com. This vulnerability is uniquely identified as CVE-2026-100891. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Technical details and a public exploit are known.

The exploit is shared for download 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.

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Productinfo

Type

Vendor

Name

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

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

Exploitinginfo

Class: Encoding error
CWE: CWE-172
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

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

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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-2026-100891 (🔒)
GCVE (CVE): GCVE-0-2026-100891
GCVE (VulDB): GCVE-100-410841
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 09/27/2026 10:00
Changes: 09/27/2026 10:00 (58)
Complete: 🔍
Submitter: WeitongLi
Cache ID: 216::103

Submitinfo

Accepted

  • Submit #917215: The Trusted Domain Project OpenDMARC 1.4.2 Improper Authentication (by WeitongLi)

Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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