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
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.
INFO
Published Date :
July 14, 2026, 6:17 p.m.
Last Modified :
July 15, 2026, 8:08 p.m.
Remotely Exploit :
Yes !
Source :
9b29abf9-4ab0-4765-b253-1875cd9b441e
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS | 134c704f-9b21-4f2e-91b3-4a467353bcc0 | |||||
| CVSS 3.1 | CRITICAL | 134c704f-9b21-4f2e-91b3-4a467353bcc0 |
Solution
- Update Mojolicious to version 9.48 or later.
- Ensure CSRF protection is enabled in the application.
- Consider disabling gzip compression if feasible.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2026-15747.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2026-15747 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2026-15747
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2026-15747 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2026-15747 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
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CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0
Jul. 15, 2026
Action Type Old Value New Value Added CVSS V3.1 AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Added SSVC {'id': 'CVE-2026-15747', 'role': 'CISA Coordinator', 'options': [{'exploitation': 'none'}, {'automatable': 'yes'}, {'technicalImpact': 'total'}], 'version': '2.0.3', 'timestamp': '2026-07-15T16:31:33.252608Z'} -
CVE Modified by af854a3a-2127-422b-91ae-364da2661108
Jul. 14, 2026
Action Type Old Value New Value Added Reference http://www.openwall.com/lists/oss-security/2026/07/14/16 -
New CVE Received by 9b29abf9-4ab0-4765-b253-1875cd9b441e
Jul. 14, 2026
Action Type Old Value New Value Added Affected [{'repo': 'https://github.com/mojolicious/mojo', 'vendor': 'SRI', 'product': 'Mojolicious', 'versions': [{'status': 'affected', 'version': '4.59', 'lessThan': '9.48', 'versionType': 'custom'}], 'packageName': 'Mojolicious', 'programFiles': ['lib/Mojolicious/Plugin/DefaultHelpers.pm', 'lib/Mojolicious/Plugin/TagHelpers.pm', 'lib/Mojolicious/Renderer.pm'], 'collectionURL': 'https://cpan.org/modules', 'defaultStatus': 'unaffected', 'programRoutines': [{'name': 'Mojolicious::Plugin::DefaultHelpers::_csrf_token'}]}] 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. Added CWE CWE-352 Added CWE CWE-204 Added Reference https://github.com/mojolicious/mojo/commit/01921fbbbbeca2d1397e082d4a647f9b84c24e27.patch Added Reference https://metacpan.org/release/SRI/Mojolicious-9.48/changes