mailcow: dockerized before 2026-11 Template Injection RCE via Domain-Wide Footer
Summary
| CVE | CVE-2026-125757 |
|---|---|
| State | PUBLISHED |
| Assigner | VulnCheck |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-11-10 16:17:23 UTC |
| Updated | 2026-11-10 16:17:23 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 9.4 CRITICAL from [email protected]
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Problem Types: CWE-1336 | CWE-1336 Improper Neutralization of Special Elements Used in a Template Engine
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.4 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/C... |
| 4.0 | CNA | CVSS | 9.4 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| 3.1 | [email protected] | Primary | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 9.1 | CRITICAL | CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
NonePrivileges Required
HighUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
HighSub Integrity
HighSub Availability
HighCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
LowPrivileges Required
HighUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Mailcow | Mailcow Dockerized | affected 2026-11 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| www.vulncheck.com/advisories/mailcow-dockerized-before-2026-11-template-injecti... | [email protected] | www.vulncheck.com | |
| github.com/mailcow/mailcow-dockerized/commit/e986803980db8b29435a2ddba5d... | [email protected] | github.com | |
| github.com/mailcow/mailcow-dockerized/security/advisories/GHSA-jgr3-fv33... | [email protected] | github.com | |
| github.com/mailcow/mailcow-dockerized/releases/tag/2026-11 | [email protected] | github.com | |
| github.com/mailcow/mailcow-dockerized/blob/55982ac74bfd35581cc44b122ab5f... | [email protected] | github.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: Faceless0x7 (en)
There are currently no legacy QID mappings associated with this CVE.