CVE-2026-25133
October CMS has Stored XSS via SVG Filter Bypass
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.
Attack profile
How easy it is to exploit
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- High
- User interaction
- Passive
What an attacker can affect
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
Exploit likelihood
What each source reports
CVE List Score used
4.8
October CMS has Stored XSS via SVG Filter Bypass
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.
- Record
CVE-2026-25133- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
EUVDEUVD-2026-22705
4.8
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.
- Record
EUVD-2026-22705- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - Updated
- 2026-11-02
GitHub AdvisoriesGHSA-gcqv-f29m-67gr
4.8
October Rain has Stored XSS via SVG Filter Bypass
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
svgto the blocked extensions in media configuration - Set
media.clean_vectorstotruein configuration (enabled by default)
References
- Reported by Pentest-Tools.com
- Record
GHSA-gcqv-f29m-67gr- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
NVD
4.8
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.
- Record
CVE-2026-25133- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSV
4.8
October CMS has Stored XSS via SVG Filter Bypass
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.
- Record
CVE-2026-25133- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - Weakness
- CWE-79
- Updated
- 2026-11-02
OSVGHSA-gcqv-f29m-67gr
4.8
October Rain has Stored XSS via SVG Filter Bypass
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
svgto the blocked extensions in media configuration - Set
media.clean_vectorstotruein configuration (enabled by default)
References
- Reported by Pentest-Tools.com
- Record
GHSA-gcqv-f29m-67gr- CVSS 4.0
- 4.8 Medium
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N - CVSS 3.1
- 4.8 Medium
CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:L/I:L/A:N - Weakness
- CWE-79
- Updated
- 2026-11-02
Affected products
Affected packages
| Package | Affected | Fixed |
|---|---|---|
october/rainPackagist |
4.0.0 to 4.1.9 | 4.1.10 |
october/rainPackagist |
through 3.7.13 | 3.7.14 |
october/rainPackagist |
4.0.0 up to 4.1.10, plus listed versions v4.0.0v4.0.1v4.0.10v4.0.11v4.0.12 Show 14 moreShow lessv4.0.13v4.0.16v4.0.2v4.0.20v4.0.22v4.0.3v4.0.6v4.0.7v4.1.0v4.1.1v4.1.4v4.1.5v4.1.6v4.1.9 |
4.1.10 |
october/rainPackagist |
before 3.7.14, plus listed versions v1.0.319v1.0.320v1.0.321v1.0.322v1.0.323 Show 45 moreShow lessv1.0.324v1.0.325v1.0.326v1.0.327v1.0.328v1.0.329v1.0.330v1.0.331v1.0.332v1.0.333v1.0.334v1.0.335v1.0.336v1.0.337v1.0.338v1.0.339v1.0.340v1.0.341v1.0.342v1.0.343v1.0.344v1.0.345v1.0.346v1.0.347v1.0.348v1.0.349v1.0.350v1.0.351v1.0.352v1.0.353v1.0.354v1.0.355v1.0.356v1.0.357v1.0.358v1.0.359v1.0.360v1.0.361v1.0.362v1.0.363v1.0.364v1.0.365v1.0.366v1.0.367v1.0.368 |
3.7.14 |
History
| Recorded | Changed | Sources |
|---|---|---|
| first indexed | CVE List, EUVD, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2026-25133 is a medium vulnerability (CVSS 4.8) in Octobercms October, published April 14, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.22%, the 12th percentile. Fixed in october/rain 4.1.10.
References
Left out here: 293 versions. The JSON record has them.