Vulnerability DatabaseCVE-2026-86009
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CVE-2026-86009
Published:October 16, 2026
Updated:October 21, 2026
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.
Related Resources (6)
https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/86xxx/CVE-2026-86009.json
https://nvd.nist.gov/vuln/detail/CVE-2026-86009
https://github.com/Mailu/Mailu/commit/f05aeb8322e2f61096af6b089d61ba6f40587d96
https://github.com/Mailu/Mailu/issues/2686
https://github.com/Mailu/Mailu/security/advisories/GHSA-crww-m82r-2wfm
https://github.com/Mailu/Mailu/pull/4072
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CVSS v4
Base Score:
8.2
Attack Vector
NETWORK
Attack Complexity
LOW
Attack Requirements
NONE
Privileges Required
HIGH
User Interaction
NONE
Vulnerable System Confidentiality
NONE
Vulnerable System Integrity
HIGH
Vulnerable System Availability
NONE
Subsequent System Confidentiality
NONE
Subsequent System Integrity
HIGH
Subsequent System Availability
NONE
CVSS v3
Base Score:
6.8
Attack Vector
NETWORK
Attack Complexity
LOW
Privileges Required
HIGH
User Interaction
NONE
Scope
CHANGED
Confidentiality
NONE
Integrity
HIGH
Availability
NONE
Weakness Type (CWE)
Improper Authorization
CWE-285
Incorrect Authorization
CWE-863
EPSS
Base Score:
0.30