Quick answers
- Is CVE-2026-25133 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-25133 being exploited in the wild.
- How severe is CVE-2026-25133?
- Medium severity, with a CVSS score of 4.8, published 14 April 2026.
- Which products and versions are affected?
- October CMS < 3.7.14, >= 4.0.0, < 4.1.10, <= 3.7.13, >= 4.0.0, <= 4.1.9; october/rain (Packagist) ECOSYSTEM:introduced=4.0.0,fixed=4.1.10.
- Is there a fix for CVE-2026-25133?
- Yes. october/rain (Packagist): upgrade to 4.1.10 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-25133 attacked?
- It is attacked over the network, in a web application.
- Am I affected by CVE-2026-25133?
- Check whether you run October CMS or october/rain (Packagist) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- october/rain (Packagist): upgrade to 4.1.10 or later
composer require october/rain:^4.1.10
Technical details
A stored cross-site scripting (XSS) vulnerability exists in October CMS due to a flaw in the regex pattern used for SVG sanitization. The pattern intended to strip 'on*' event handler attributes (like onclick or onload) can be bypassed by exploiting how the regex matches attribute boundaries. An attacker with backend access and 'media.library.create' permissions can upload a crafted SVG file. When a superuser views or embeds this SVG, the embedded JavaScript executes in their context, potentially leading to privilege escalation. The issue is fixed in versions 3.7.14 and 4.1.10.
Affected products
- October CMS October CMS < 3.7.14, >= 4.0.0, < 4.1.10
Identifiers
- CVE-2026-25133
- GHSA-gcqv-f29m-67gr
Timeline
- 2026-04-14: advisory
- 2026-04-14: patched