CVE-2026-25133

October CMS has Stored XSS via SVG Filter Bypass

MEDIUM
4.8
CVSS Score
Published: April 14, 2026 at 08:47 PM UTC
Updated: July 25, 2026 at 11:21 AM UTC
1 product affected across 1 vendorOctober

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Severity
MEDIUM4.8
Exploit prediction
EPSS 0.2%
SSVC
No known exploit

Description

October is a Content Management System (CMS) and web platform. Versions prior to 3.7.14 and 4.1.10 contain a stored cross-site scripting (XSS) vulnerability in the SVG sanitization logic. The regex pattern used to strip event handler attributes (such as onclick or onload) could be bypassed using a crafted payload that exploits how the pattern matches attribute boundaries, allowing malicious SVG files to be uploaded through the Media Manager with embedded JavaScript. Exploitation could lead to privilege escalation if a superuser views or embeds the malicious SVG, and requires authenticated backend access with media upload permissions. The SVG must be viewed or embedded in a page for the payload to trigger. This issue has been fixed in versions 3.7.14 and 4.1.10.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v ≤ 3.7.13v < 3.7.14v < 4.1.104.0.0 ≤ v ≤ 4.1.9
Affected range stops below 3.7.14, so it looks safe — our inference, not a vendor statement
Affected range stops below 4.1.10, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet. What the record does show:

References (1)

SSVC — Action Prioritization

SSVCNo known exploitNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

4.8MEDIUMGitHub_M
Vector?

Quick Info

StatusANALYZED
CWE
CWE-79

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