Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle. _csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden `csrf_token` input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle. An attacker able to query it can recover the token and pass csrf_protect validation.
History

Mon, 27 Jul 2026 15:30:00 +0000

Type Values Removed Values Added
First Time appeared Sri
Sri mojolicious
Vendors & Products Sri
Sri mojolicious

Wed, 15 Jul 2026 17:30:00 +0000

Type Values Removed Values Added
Metrics cvssV3_1

{'score': 9.1, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N'}

ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}


Tue, 14 Jul 2026 17:45:00 +0000

Type Values Removed Values Added
Description Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle. _csrf_token generates and caches one token per session and returns the same value on every call, and _csrf_field places that value in a hidden `csrf_token` input. When a response carrying the token also echoes attacker-controlled input and is gzip-compressed, the chosen values and the resulting compressed lengths form a BREACH oracle. An attacker able to query it can recover the token and pass csrf_protect validation.
Title Mojolicious versions from 4.59 before 9.48 for Perl expose a stable representation of the session CSRF token to a BREACH compression oracle
Weaknesses CWE-204
CWE-352
References

cve-icon MITRE

Status: PUBLISHED

Assigner: CPANSec

Published: 2026-07-14T17:07:32.593Z

Updated: 2026-07-15T16:32:58.629Z

Reserved: 2026-07-14T15:03:43.632Z

Link: CVE-2026-15747

cve-icon Vulnrichment

Updated: 2026-07-14T19:30:12.894Z

cve-icon NVD

No data.

cve-icon Redhat

No data.