EUVD-2026-88055
GHSA-h88r-m2wp-c7v2
Severity by source
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Remote and unauthenticated (AV:N/PR:N) but requires a specific IDN U-label encoding corner case (AC:H); primary impact is DMARC bypass (I:L) with possible processing error (A:L) and no real confidentiality loss (C:N).
Primary rating from Vendor (VulDB).
CVSS VectorVendor: VulDB
Lifecycle Timeline
3DescriptionCVE.org
A vulnerability has been found in Trusted Domain Project OpenDMARC up to 1.4.2. Affected by this issue is the function opendmarc_policy_query_dmarc in the library libopendmarc/opendmarc_policy.c of the component Internationalized Domain Name Handler. Such manipulation leads to encoding error. It is possible to launch the attack remotely. The exploit has been disclosed to the public and may be used. The vendor was contacted early about this disclosure but did not respond in any way.
AnalysisAI
OpenDMARC through 1.4.2 can mishandle Internationalized Domain Name labels during DMARC policy lookup in opendmarc_policy_query_dmarc, allowing a remote, unauthenticated attacker to trigger an encoding error with a crafted email and potentially distort DMARC evaluation on internet-facing mail servers that run OpenDMARC as a milter/library, typically with Postfix or Sendmail. Publicly available exploit code exists, but the supplied data does not confirm active exploitation or a CISA KEV entry. …
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Attack ChainAIDerived
Hypothetical attack flow derived from CVE metadata
Vulnerability AssessmentAI
| Exploitation | Requires OpenDMARC (<=1.4.2) deployed as the DMARC-checking milter/library on an internet-facing mail server (typically with Postfix or Sendmail), processing inbound mail. … Additional conditions and limiting factors are described in the full assessment. |
| Risk Assessment | This is a moderate, integrity-oriented issue rather than a high-urgency priority. … Full risk analysis with EPSS, KEV, and SSVC signal comparison available after sign-in. |
| Exploit Scenario | Full exploit scenario with step-by-step reproduction available after sign-in. |
| Remediation | No vendor-released patch identified at time of analysis, and the vendor did not respond to the disclosure; monitor the upstream OpenDMARC project and https://vuldb.com/vuln/410841 for a fixed release beyond 1.4.2 and apply it when available. … Detailed patch versions, workarounds, and compensating controls in full report. |
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OpenDMARC through 1.3.2 and 1.4.x through 1.4.0-Beta1 has improper null termination in the function opendmarc_xml_parse
OpenDMARC 1.4.2 contains a null pointer dereference vulnerability in /OpenDMARC/libopendmarc/opendmarc_policy.c. Rated h
OpenDMARC 1.4.1 and 1.4.1.1 allows remote attackers to cause a denial of service (NULL pointer dereference and applicati
OpenDMARC through 1.3.2 and 1.4.x through 1.4.0-Beta1 is prone to a signature-bypass vulnerability with multiple From: a
Email authentication bypass in OpenDMARC up to 1.4.2 allows remote unauthenticated attackers to spoof sender domains by
DMARC authentication bypass in Trusted Domain Project OpenDMARC through 1.4.2 lets a remote attacker defeat the DMARC an
Integer overflow in OpenDMARC through 1.4.2 allows unauthenticated remote attackers to corrupt DMARC policy-percentage h
DMARC policy evaluation in Trusted Domain Project OpenDMARC through 1.4.2 can be bypassed by mail carrying sending-domai
Malformed DMARC policy tags (fo, rf, ri, pct, sp, adkim, aspf, rua, ruf) supplied in attacker-controlled DNS TXT records
Off-by-one bounds error in Trusted Domain Project OpenDMARC through 1.4.2 lets a remote, unauthenticated attacker send a
A NULL pointer dereference in the Trusted Domain Project's OpenDMARC (up to and including 1.4.2) can crash the mail filt
OpenDMARC through 1.3.2 and 1.4.x allows attacks that inject authentication results to provide false information about t
Same weakness CWE-172 – Encoding Error
View allSame technique Information Disclosure
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External POC / Exploit Code
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