CVE-2026-125757

CRITICAL 9.1

mailcow: dockerized before 2026-11 Template Injection RCE via Domain-Wide Footer

CVSS Score

9.1

EPSS Score

0.0%

EPSS Percentile

0th

mailcow: dockerized before 2026-11 contains a server-side template injection vulnerability that allows domain administrators to execute commands in the shared rspamd container by storing a malicious domain-wide footer. Attackers can embed a Jinja macro with an os.execute default value, rendered by the rspamd MOO_FOOTER prefilter, to read or inject mail for every tenant and disable filtering.

CWE	CWE-1336
Vendor	mailcow
Product	mailcow: dockerized
Published	Nov 10, 2026
Last Updated	Nov 10, 2026

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CVSS v3 Breakdown

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

None

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

Affected Versions

mailcow / mailcow: dockerized

0 < 2026-11

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jgr3-fv33-x43c github.com: https://github.com/mailcow/mailcow-dockerized/commit/e986803980db8b29435a2ddba5d9760737a818e3 github.com: https://github.com/mailcow/mailcow-dockerized/releases/tag/2026-11 github.com: https://github.com/mailcow/mailcow-dockerized/blob/55982ac74bfd35581cc44b122ab5fc659e3ae90a/data/conf/rspamd/lua/rspamd.local.lua#L847-L850 vulncheck.com: https://www.vulncheck.com/advisories/mailcow-dockerized-before-2026-11-template-injection-rce-via-domain-wide-footer

Credits

Faceless0x7