How severe is CVE-2026-25133?

No CVSS score has been assigned to CVE-2026-25133 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2026-25133?

CVE-2026-25133 affects the following packages: october/rain (Packagist), october/rain (Packagist). Ecosystems affected: Packagist.

How do I fix CVE-2026-25133?

Update october/rain to 4.1.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-25133 is resolved across your whole dependency graph.

How do I detect CVE-2026-25133 in my Packagist dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for october/rain, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2026-25133 if there is no patch (or I can't update yet)?

Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Is CVE-2026-25133 actively exploited in the wild?

No public exploit code has been indexed for CVE-2026-25133 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2026-25133?

CVE-2026-25133 has an EPSS (Exploit Prediction Scoring System) score of 0.2%, placing it in the 12th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2026-25133?

CVE-2026-25133 is classified as Cross-site Scripting (XSS) (CWE-79). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation. This is a high-impact weakness class that often enables remote code execution or data exposure.

When was CVE-2026-25133 published, and has it been updated?

CVE-2026-25133 was published on April 14, 2026 and was last updated on October 28, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐘 Packagist

Not in CISA KEV

CVE-2026-25133 — rain

CVE-2026-25133 is a Cross-site Scripting (XSS) vulnerability in october/rain. A fix is available for october/rain — see the affected versions and patch details below.

October CMS has Stored XSS via SVG Filter Bypass

Also known asGHSA-gcqv-f29m-67gr

Published

Apr 14, 2026

Updated

Oct 28, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Nov 5, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2026-25133.

EPSS Exploitation Probability

via FIRST.org ↗

0.2%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs12th percentile — riskier than 12% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

2 pkgs affected

🐘october/rain🐘october/rain

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.

Description

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 Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🐘Packagist	`october/rain`	≥ 4.0.0&&< 4.1.10	4.1.10`composer require october/rain:^4.1.10`
🐘Packagist	`october/rain`	all versions	3.7.14`composer require october/rain:^3.7.14`

Affected Products

1 product · 2 configurations

Application

octoberoctobercms

≥ 4.0.0 && ≤ 4.1.9

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for october/rain, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update october/rain to 4.1.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-25133 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.

Frequently Asked Questions

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 vulne

O3 Security · Impact-Aware SCA

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CVE-2026-25133 — rain

Exploitation Status

No confirmed exploitation observed yet

EPSS Exploitation Probability

Real-World Exposure

Description

Impact

Patches

Workarounds

References

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2026-25133 in your dependencies?