High 8.2Published Oct 16, 2026

CVE-2026-86009Mailu: Domain managers can allow themselves to spoof on other hosted domains they should not control

Updated under an hour ago (Oct 26, 2026, 4:10 AM ET)

Does this affect you?

It affects Mailu. Add what you run to find out whether that includes you.

EPSS puts the chance of exploitation in the next 30 days at 0.38%, higher than 31% of scored CVEs.

Do this next

Start free and add your stack

Free account, 1 product

Every CVE for Mailu

Exploited in the last 30 days

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.

CVSS: 8.2 HIGH (v4.0, CNA)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
Weakness (CWE): CWE-285, CWE-863
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): 0.38% (percentile 31)
Assigned by: GitHub_M
NVD analysis: Deferred
Record last updated: Oct 20, 2026
First seen by InfoSec Signals: Oct 16, 2026

Affected products

Affected products

Mailu Mailu mailu:mailu (from the name)	before f05aeb8322e2f61096af6b089d61ba6f40587d96	CNA record

References

https://github.com/Mailu/Mailu/security/advisories/GHSA-crww-m82r-2wfmx-refsource-confirm
https://github.com/Mailu/Mailu/issues/2686x-refsource-misc
https://github.com/Mailu/Mailu/pull/4072x-refsource-misc
https://github.com/Mailu/Mailu/commit/f05aeb8322e2f61096af6b089d61ba6f40587d96x-refsource-misc

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.