Mautic vulnerability

ImpactThe attacker can validate if a user exists by checking the time login returns. This timing difference can be used to enumerate valid usernames, after which an attacker could attempt brute force attacks. PatchesThis vulnerability has been patched, implementing a timing-safe form login authenticator that ensures consistent response times regardless of whether a user exists or not. Technical DetailsThe vulnerability was caused by different response times when: * A valid username was provided (password hashing occurred) * An invalid username was provided (no password hashing occurred) The fix introduces a TimingSafeFormLoginAuthenticator that performs a dummy password hash verification even for non-existent users, ensuring consistent timing. WorkaroundsNo workarounds are available. Users should upgrade to the patched version. References * https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/03-Identity_Management_Testing/04-Testing_for_Account_Enumeration_and_Guessable_User_Account

Published 3 Sep 2025Updated 19 Oct 20261 sources
CVSS 5.9

What happened

ImpactThe attacker can validate if a user exists by checking the time login returns. This timing difference can be used to enumerate valid usernames, after which an attacker could attempt brute force attacks. PatchesThis vulnerability has been patched, implementing a timing-safe form login authenticator that ensures consistent response times regardless of whether a user exists or not. Technical DetailsThe vulnerability was caused by different response times when: * A valid username was provided (password hashing occurred) * An invalid username was provided (no password hashing occurred) The fix introduces a TimingSafeFormLoginAuthenticator that performs a dummy password hash verification even for non-existent users, ensuring consistent timing. WorkaroundsNo workarounds are available. Users should upgrade to the patched version. References * https://owasp.org/www-project-web-security-testing-guide/latest/4-Web_Application_Security_Testing/03-Identity_Management_Testing/04-Testing_for_Account_Enumeration_and_Guessable_User_Account

Affected versions

Mautic: >= 4.4.0 through before < 4.4.17 (semver); >= 5.0.0-alpha through before < 5.2.8 (semver); >= 6.0.0-alpha through before < 6.0.5 (semver) Fixed: See vendor advisory.

Why it matters

Review the vendor advisory and exposure of the affected product to determine operational impact.

Detection & mitigation

  • Apply vendor-provided updates or mitigations.
  • Review affected product exposure and access logs.

Public PoC references

No public PoC reference has passed the current publication threshold.