[ CVE-2026-86009 · Published 16 Oct 2026 ]
Vulnerability in Mailu
CVSS 8.2
EPSS <1%No fix listed yet
[ Why it matters ]Priority signals
- Public proof-of-concept exploit exists (CISA SSVC)
[ Description ]Official 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.
[ Fixes ]Fixes and patches
No fix or interim patch is linked from our sources yet. Check the vendor references below and limit exposure of affected systems until a fix is available.