---
title: "CVE-2026-101281: Trusted Domain Project OpenDMARC - Authentication Bypass"
description: "Trusted Domain Project OpenDMARC <= 1.4.2 contains an authentication bypass caused by improper handling in opendmarc_sp2_find_mailfrom_domain function in SPF Macro Handler, letting remote attackers bypass authentication, exploit requires crafted input."
url: https://panop.io/threat-heartbeat/CVE-2026-101281/
---

# CVE-2026-101281 Trusted Domain Project OpenDMARC - Authentication Bypass

Trusted Domain Project OpenDMARC <= 1.4.2 contains an authentication bypass caused by improper handling in opendmarc\_sp2\_find\_mailfrom\_domain function in SPF Macro Handler, letting remote attackers bypass authentication, exploit requires crafted input.

CVSS base score 7.3 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Not required

EPSS

0.41% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-101281)

## Details

Type

Authentication Bypass

Impact

Broken Authentication

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L

Published

29 September 2026

Updated

15 October 2026

Weakness

[CWE-287](https://cwe.mitre.org/data/definitions/287.html)

## Vendor fix

Apply the patch c48a74c758677fc5272a73eff15ffdbf8afda1a6 or update to a fixed version.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-101281](https://nvd.nist.gov/vuln/detail/CVE-2026-101281)
- [https://vuldb.com/submit/918284](https://vuldb.com/submit/918284)
- [https://vuldb.com/vuln/411038](https://vuldb.com/vuln/411038)
- [https://vuldb.com/vuln/411038/cti](https://vuldb.com/vuln/411038/cti)
- [https://xuyongzhe-vt.github.io/share/opendmarc-spf-postmaster-macro.html](https://xuyongzhe-vt.github.io/share/opendmarc-spf-postmaster-macro.html)
- [https://github.com/trusteddomainproject/OpenDMARC/commit/c48a74c758677fc5272a73eff15ffdbf8afda1a6](https://github.com/trusteddomainproject/OpenDMARC/commit/c48a74c758677fc5272a73eff15ffdbf8afda1a6)
- [https://github.com/trusteddomainproject/OpenDMARC/issues/262](https://github.com/trusteddomainproject/OpenDMARC/issues/262)
- [https://github.com/trusteddomainproject/OpenDMARC/pull/328](https://github.com/trusteddomainproject/OpenDMARC/pull/328)
- [https://vuldb.com/cve/CVE-2026-101281](https://vuldb.com/cve/CVE-2026-101281)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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