CVE-2026-125757NVD
Vulnerability Summary
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.
CVSS v4.0 Base Metrics — Score 9.4 (CRITICAL)
Attack VectorNetwork
Attack ComplexityLow
Attack RequirementsNone
Privileges RequiredHigh
User InteractionNone
Confidentiality (Vulnerable System)High
Integrity (Vulnerable System)High
Availability (Vulnerable System)High
Confidentiality (Subsequent System)High
Integrity (Subsequent System)High
Availability (Subsequent System)High
CVSS v3.1 Base Metrics — Score 9.1 (CRITICAL)
Attack VectorNetwork
Attack ComplexityLow
Privileges RequiredHigh
User InteractionNone
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
Affected & Patched Versions
- mailcow mailcow: dockerized < 2026-11
- mailcow mailcow: dockerized 2026-11
External References
- https://github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jgr3-fv33-x43c
- https://github.com/mailcow/mailcow-dockerized/commit/e986803980db8b29435a2ddba5d9760737a818e3
- https://github.com/mailcow/mailcow-dockerized/releases/tag/2026-11
- https://github.com/mailcow/mailcow-dockerized/blob/55982ac74bfd35581cc44b122ab5fc659e3ae90a/data/conf/rspamd/lua/rspamd.local.lua#L847-L850
- https://www.vulncheck.com/advisories/mailcow-dockerized-before-2026-11-template-injection-rce-via-domain-wide-footer