ZDF
Sign inSign up

Vulnerabilities

Vulnerability · CVE-2026-40878

mailcow: dockerized is an open source groupware/email suite based on docker.

Published Apr 21, 2026 · catalog updated Jun 17, 2026 · mailcow: dockerized is an

Check if you run it

No confirmed exploitation is on record for CVE-2026-40878. EPSS is 0.98%. Act only if a listed version of mailcow: dockerized is an is installed.

Gaps on this record

  • The stored product name is a package slug. The name on this page is taken from the title (mailcow: dockerized is an).
  • 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.
Severity
Low2.1
Known exploitation
Not in CISA/VulnCheck KEV
EPSS
0.98%
Remediation
Advisory link
Affected products
See sources for product scope

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.

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.

How to fix CVE-2026-40878

What to do

Three questions, each answered from this record only. Confirm the vendor advisory before you patch.

Should you patch?

No confirmed exploitation is on record for CVE-2026-40878. EPSS is 0.98%. Act only if a listed version of mailcow: dockerized is an is installed.

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-79: Cross-site Scripting (XSS). EPSS 0.98%. There is no CISA KEV listing. No Exploit-DB or Metasploit reference is linked. Use the source links for the original advisory.

Technology hubs

Docker security

Code

The project this record applies to. Exploit listings stay in References.

Timeline

Detection, updates, and resolution for this record.

  1. 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

  2. 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
  • FIRST EPSSExploitation probabilityCVE-2026-40878

    30-day exploitation probability 1.0%

    first.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

References

Freshness

Last verified in this catalog Oct 18, 2026. Significant claims (KEV, EPSS, CVSS, affected ranges) come from the source rows above — open the original publisher for the authoritative advisory.