{"id":"CVE-2026-86009","title":"Mailu: Domain managers can allow themselves to spoof on other hosted domains they should not control","summary":"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 ena…","severity":"high","cvss":8.2,"cvssVector":"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","cvssSource":"cna","cwe":["CWE-285","CWE-863"],"vendor":"Mailu","product":"Mailu","affected":["Mailu < f05aeb8322e2f61096af6b089d61ba6f40587d96"],"ssvc":{"exploitation":"poc","automatable":"no","technicalImpact":"partial","timestamp":"2026-10-21T02:26:25.611618Z"},"exploitAvailable":true,"published":"2026-10-16","updated":"2026-10-21","sourceUpdated":"2026-10-21T02:26:54.464Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-86009","references":[{"url":"https://github.com/Mailu/Mailu/security/advisories/GHSA-crww-m82r-2wfm","label":"https://github.com/Mailu/Mailu/security/advisories/GHSA-crww-m82r-2wfm"},{"url":"https://github.com/Mailu/Mailu/issues/2686","label":"https://github.com/Mailu/Mailu/issues/2686"},{"url":"https://github.com/Mailu/Mailu/pull/4072","label":"https://github.com/Mailu/Mailu/pull/4072"},{"url":"https://github.com/Mailu/Mailu/commit/f05aeb8322e2f61096af6b089d61ba6f40587d96","label":"https://github.com/Mailu/Mailu/commit/f05aeb8322e2f61096af6b089d61ba6f40587d96"}],"tags":["cve.org","exploit-available"],"epss":0.00378,"epssPercentile":0.31559,"ingestedAt":"2026-10-16T17:24:46.886Z","slug":"CVE-2026-86009","body":"## Overview\n\nMailu 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.\n\n## Affected\n\n- `Mailu < f05aeb8322e2f61096af6b089d61ba6f40587d96`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"midnight","depthScore":57,"depthScoreParts":{"impact":45.1,"likelihood":0.1,"exploitation":12,"ransomware":0},"changes":[{"seq":226796,"id":"CVE-2026-86009","ts":1792550345124,"field":"exploit_available","old":"false","new":"true"}]}