CVE-2026-40878
mailcow: dockerized is an open source groupware/email suite based on docker.
Published Apr 21, 2026 · corrected/updated Jun 17, 2026 · evidence confidence medium
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the mailcow web interface passes the raw to Twig as a global template variable and renders it inside a JavaScript string literal in the helper of , relying on Twig's default HTML auto-escaping instead of the context-appropriate escaping strategy. In addition, the Twig helper merges all current parameters into the language-switching links on the login page, so attacker-supplied parameters are reflected and preserved across navigation. Version 2026-03b fixes the vulnerability.
Grounded briefings
Catalog interpretations for three audiences. Each brief cites ingested metadata and the original advisories below. They are not independent research and they do not invent exploit steps.
Executive
CVE-2026-40878 is a low public vulnerability record for this product. It is not currently listed in the CISA Known Exploited catalog. Check the linked vendor or CERT advisories for patch status. This summary is a catalog interpretation of the ingested metadata and cites the original advisories below.
System administrator
Identify whether this product is in your estate, then compare installed versions with the affected ranges. Affected version ranges have not been ingested yet. Check the linked vendor or CERT advisories for patch status. Prefer the vendor or distribution advisory linked in Sources before changing production systems. This is a catalog interpretation, not a runbook.
Security analyst
Signals on file: CVSS 2.1. It is not currently listed in the CISA Known Exploited catalog. Weakness classes: CWE-79. Sources contributing to this record: cve_org, nvd. Public exploit references, when present, are outbound links only and are not proof of active exploitation. This is a catalog interpretation of stored metadata.
Exploitation and remediation
Exploitation evidence
Not listed as known exploited in CISA KEV. Not in the CISA KEV catalog.
Patch and remediation
No required-action text is stored yet. Use the vendor or CERT links in Sources for patch availability.
Safe detection guidance
Compare installed versions with the affected ranges below and verify the advisory from the original publisher. This site stores metadata and outbound links only; it does not ship exploit code or proof-of-concept payloads.
Technology hubs
Code
The project this record applies to. Exploit listings stay in References.
Timeline
Detection, updates, and resolution for this record.
Apr 21, 2026 · NIST NVD
Detected
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the mailcow web interface passes the raw to Twig as a global template variable and renders it inside a JavaScript string literal in the helper of , relying on Twig's default HTML auto-escaping instead of the context-appropriate escaping strategy. In addition, the Twig helper merges all curre
Jun 17, 2026 · NIST NVD
Updated
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the mailcow web interface passes the raw to Twig as a global template variable and renders it inside a JavaScript string literal in the helper of , relying on Twig's default HTML auto-escaping instead of the context-appropriate escaping strategy. In addition, the Twig helper merges all curre
Sources
- CVE.orgVulnerability recordCVE-2026-40878
Official CVE identifier
cve.org - NIST NVDVulnerability recordCVE-2026-40878
mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the mailcow web interface passes the raw to Twig as a global template variable and renders it inside a JavaScript string literal in the `setLang()
nvd.nist.gov