CVE-2026-15747

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.

CVSS v3 9.1 CRITICAL

9.1^/10

CVSS v3 : CRITICAL

Vector :

Exploitability : 3.9 / Impact : 5.2

Attack Vector NETWORK

Attack Complexity LOW

Privileges Required NONE

User Interaction NONE

Confidentiality Impact HIGH

Integrity Impact HIGH

Availability Impact NONE

Scope UNCHANGED

References

Link	Resource
https://github.com/mojolicious/mojo/commit/01921fbbbbeca2d1397e082d4a647f9b84c24e27.patch
https://metacpan.org/release/SRI/Mojolicious-9.48/changes
http://www.openwall.com/lists/oss-security/2026/07/14/16

Configurations

No configuration.

History

15 Jul 2026, 17:16

Type	Values Removed	Values Added
CVSS	v2 : ~~unknown~~ v3 : ~~unknown~~	v2 : unknown v3 : 9.1

14 Jul 2026, 20:16

Type	Values Removed	Values Added
References		() http://www.openwall.com/lists/oss-security/2026/07/14/16 -

14 Jul 2026, 18:17

Type	Values Removed	Values Added
New CVE

Information

Published : 2026-07-14 18:17

Updated : 2026-07-15 20:08

NVD link : CVE-2026-15747

Mitre link : CVE-2026-15747

CVE.ORG link : CVE-2026-15747

JSON object : View

Products Affected

No product.

CWE

CWE-204

Observable Response Discrepancy

CWE-352

Cross-Site Request Forgery (CSRF)

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