Vulnerability · CVE-2026-86009
Mailu is a mail server distributed as a set of Docker images.
Published Oct 16, 2026 · catalog updated Oct 21, 2026 · Mailu is a mail
Open the advisory
Exploitation likelihood is not on this record for CVE-2026-86009. A missing EPSS score is not a low risk. Compare Mailu is a mail with the linked advisory before you change production.
Gaps on this record
- The stored product name is a package slug. The name on this page is taken from the title (Mailu is a mail).
- No version range is stored. A customer cannot check an installed version against this record.
- No vendor fix or required action is stored. Compare the linked advisory before you change production.
- EPSS is missing. A missing score is not a low risk.
- Severity
- High8.2
- Known exploitation
- Not in CISA/VulnCheck KEV
- EPSS
- Awaiting synchronization with FIRST
- Remediation
- Advisory link
- Affected products
- See sources for product scope
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.
No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.
How to fix CVE-2026-86009
Recommended remediation
A patch or advisory reference is linked. Open the original publisher for availability by product version.
Official advisories
What to do
Three questions, each answered from this record only. Confirm the vendor advisory before you patch.
Should you patch?
Exploitation likelihood is not on this record for CVE-2026-86009. A missing EPSS score is not a low risk. Compare Mailu is a mail with the linked advisory before you change production.
Which versions are affected?
Affected version ranges are not on this record. Compare the installed version with the linked vendor advisory before you change production.
What should an analyst verify?
CWE-285: Improper Authorization; CWE-863: Incorrect Authorization. EPSS is not on this record yet. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Oct 16, 2026 · NIST NVD
Detected
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 addr
Oct 21, 2026 · NIST NVD
Updated
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 addr
Sources
- CVE.orgVulnerability recordCVE-2026-86009
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-86009
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
nvd.nist.gov
References
Freshness
Last verified in this catalog Oct 21, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.