CVE-2026-40873

Summary

mailcow: dockerized is an open source groupware/email suite based on docker. In versions prior to 2026-03b, the Quarantine details modal injects attachment filenames into HTML without escaping, allowing arbitrary HTML/JS execution. An attacker can deliver an email with a crafted attachment name so that when an admin views the quarantine item, JavaScript executes in their browser, taking over their account. Version 2026-03b fixes the vulnerability.

Affected Software

VendorProductVersion RangeStatus
mailcowmailcow-dockerized< 2026-03baffected

Weaknesses

  • CWE-79: CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
  • CWE-80: CWE-80: Improper Neutralization of Script-Related HTML Tags in a Web Page (Basic XSS)

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: poc
    • Automatable: no
    • Technical Impact: total

Additional References

References