CVE-2026-86009

Mailu: Domain managers can allow themselves to spoof on other hosted domains they should not control

Published Oct 16, 2026 CVSS 4.0 · 8.2 High EPSS < 1% KEV · Not listed
Description
Mailu is a mail server distributed as a set of Docker images. Prior to f05aeb8322e2f61096af6b089d61ba6f40587d96, domain managers can enable spoofing for hosted domains they do not control. A potentially malicious domain administrator enables spoofing for another hosted domain and can send emails that are authenticated with DKIM/SPF for domains they should not be able to. This vulnerability is addressed by f05aeb8322e2f61096af6b089d61ba6f40587d96.

Remediation

No solution or workaround provided in the CVE record

Tracking

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Advisories

No advisories available
History
Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'no', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Type Values Removed Values Added
First Time appeared Mailu
Mailu mailu
Vendors & Products Mailu
Mailu mailu
Type Values Removed Values Added
Description Mailu is a mail server distributed as a set of Docker images. Prior to f05aeb8322e2f61096af6b089d61ba6f40587d96, domain managers can enable spoofing for hosted domains they do not control. A potentially malicious domain administrator enables spoofing for another hosted domain and can send emails that are authenticated with DKIM/SPF for domains they should not be able to. This vulnerability is addressed by f05aeb8322e2f61096af6b089d61ba6f40587d96.
Title Mailu: Domain managers can allow themselves to spoof on other hosted domains they should not control
Weaknesses CWE-285
CWE-863
References
Metrics cvssV4_0

{'score': 8.2, 'vector': 'CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:H/VA:N/SC:N/SI:H/SA:N'}

Weaknesses

Sources

Status
PUBLISHED
Assigner
GitHub_M
Published
Updated
Oct 21, 2026, 2:26 AM
Reserved
Sep 4, 2026, 7:17 PM
Status
Deferred
Published
Oct 16, 2026, 5:17 PM
Modified
Oct 21, 2026, 3:17 AM