Bug 2542363 (CVE-2026-101015)

Summary: CVE-2026-101015 opendmarc: OpenDMARC: DMARC policy bypass via Unicode dot character equivalence in policy.c Domain Handler
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
Version: unspecifiedKeywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in OpenDMARC. A remote attacker can bypass Domain-based Message Authentication, Reporting, and Conformance (DMARC) policy checks by submitting domain names containing equivalent Unicode dot characters. Due to improper input validation in domain handling, the service fails to enforce policy restrictions properly, allowing unauthorized or spoofed emails to evade detection.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2542427, 2542428    
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Description OSIDB Bzimport 2026-09-28 08:41:34 UTC 
A flaw has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this issue is some unknown functionality of the file policy.c of the component Domain Handler. Executing a manipulation can lead to improper validation of unsafe equivalence in input. The attack may be launched remotely. The exploit has been published and may be used. The vendor was contacted early about this disclosure but did not respond in any way.