Medium

October Rain has Stored XSS via SVG Filter Bypass

  • Disclosed: 14.04.2026
  • Updated: 11.10.2026 10:22

A stored cross-site scripting (XSS) vulnerability was identified in the SVG sanitization logic. The regex pattern used to strip on* event handler attributes could be bypassed using a crafted payload that exploits how the pattern matches attribute boundaries.

Impact

  • Stored XSS via malicious SVG files uploaded through the Media Manager
  • Could allow privilege escalation if a superuser views or embeds the malicious SVG
  • Requires authenticated backend access with media upload permissions (media.library.create)
  • SVG must be viewed or embedded in a page to trigger

Patches

The vulnerability has been patched in v3.7.14 and v4.1.10. All users are encouraged to upgrade to the latest patched version.

Workarounds

If upgrading immediately is not possible:

  • Disable SVG uploads by adding svg to the blocked extensions in media configuration
  • Set media.clean_vectors to true in configuration (enabled by default)

References

  • Reported by Pentest-Tools.com

Affected software

Click a technology to see all vulnerabilities affecting it.

PlatformPackageVulnerable versionsFixed in
Composer package october/rain >= 4.0.0, < 4.1.10, < 3.7.14 4.1.10, 3.7.14

References

CVSS score 4.8/10
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N
Weakness (CWE)
CWE-79
Platform
Composer
Package
october/rain
Disclosed
14.04.2026
Updated
11.10.2026 10:22

Sources and licenses

OSV / GitHub Advisory Database - GHSA-gcqv-f29m-67gr - CC BY 4.0

Vulnerability history: october/rain

All published vulnerabilities of this package (Composer package), newest first. Shows whether this is a one-off slip or a package that needs watching.

Total entries
6
First → latest
08.2020 04.2026
Without a fix
0
Exploited in attacks
0

Severity breakdown

  • Critical 1
  • Medium 5

Disclosures per year

  1. 2020: 1
  2. 2021: 1
  3. 2022: 1
  4. 2023: 0
  5. 2024: 0
  6. 2025: 0
  7. 2026: 3
  1. October Rain has Stored XSS via SVG Filter Bypass this entry
    Medium · 4.8 CVE-2026-25133 >= 4.0.0, < 4.1.10, < 3.7.14 4.1.10, 3.7.14
  2. Medium · 4.9 CVE-2026-25125 >= 4.0.0, < 4.1.10, < 3.7.14 4.1.10, 3.7.14
  3. Medium · 4.9 CVE-2026-22692 >= 4.0.0, < 4.1.5, < 3.7.13 4.1.5, 3.7.13
  4. Medium · 5.4 CVE-2017-15284 < 1.0.426 1.0.426
  5. Critical · 9.8 CVE-2021-3311 < 1.0.472, >= 1.1.0, < 1.1.2 1.0.472, 1.1.2
  6. Medium · 6.1 CVE-2020-15128 >= 1.0.319, < 1.0.468 1.0.468

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