# CVE-2026-125339: Winter CMS: CSRF through AJAX handler names reachable as backend page actions

Status: published. Published: 2026-11-10. Updated: 2026-11-12.

Winter CMS is a content management system built on the Laravel PHP framework. From 1.0.319 until 1.2.14, Backend\Classes\Controller::actionExists() accepts public handler-shaped methods as page actions, so a top-level GET request can invoke state-changing backend AJAX handlers without a CSRF token. Because backend routes use Route::any, CSRF validation skips GET, and the default SameSite=Lax session cookie is sent on cross-site navigation, an unauthenticated attacker can induce an authorized backend user to follow a link such as /backend/system/eventlogs/index_onEmptyLog. Affected handlers in the backend, CMS, and system modules can truncate logs, reset settings, alter backend user state, or delete CMS templates, while URL path segments can select a target record. This issue is fixed in version 1.2.14.

## Remediation

- fix: winter/wn-backend-module (Packagist): OSV reports a fixed version 1.2.14. Check the advisory for supported release branches. (source: OSV GHSA-p2ch-c2c3-4xm5) — https://github.com/advisories/GHSA-p2ch-c2c3-4xm5

## Affected products and versions

- wintercms / winter: >= 1.0.319, < 1.2.14 (affected). Source: CNA: GitHub_M
-  / winter/wn-backend-module (winter/wn-backend-module): v1.0.473 (affected, Packagist); v1.0.474 (affected, Packagist); v1.0.475 (affected, Packagist); v1.1.10 (affected, Packagist); v1.1.11 (affected, Packagist); v1.1.2 (affected, Packagist); v1.1.3 (affected, Packagist); v1.1.4 (affected, Packagist); v1.1.5 (affected, Packagist); v1.1.6 (affected, Packagist); v1.1.7 (affected, Packagist); v1.1.8 (affected, Packagist); v1.1.9 (affected, Packagist); v1.2.0 (affected, Packagist); v1.2.1 (affected, Packagist); v1.2.10 (affected, Packagist); v1.2.11 (affected, Packagist); v1.2.12 (affected, Packagist); v1.2.13 (affected, Packagist); v1.2.2 (affected, Packagist); v1.2.3 (affected, Packagist); v1.2.4 (affected, Packagist); v1.2.5 (affected, Packagist); v1.2.6 (affected, Packagist); v1.2.7 (affected, Packagist); v1.2.8 (affected, Packagist); v1.2.9 (affected, Packagist); Ecosystem version events: introduced 1.0.319; fixed 1.2.14. Source: OSV GHSA-p2ch-c2c3-4xm5

## Severity and prioritization

- CVSS 3.1: 6.1 (medium); CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:H; source: CNA: GitHub_M

- CVSS 3.1: 6.1 (medium); CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:H; source: NVD: security-advisories@github.com

- CISA KEV: No listing in collected sources

- EPSS: 0.18% as of 2026-11-12; percentile 7.12%

- SSVC: exploitation none; automatable no; technical impact partial; source ADP: CISA-ADP

- Weaknesses: CWE-352

## Exploit evidence

No exploit evidence in collected sources. This is not proof of no exploitation.

## References

- https://github.com/wintercms/winter/security/advisories/GHSA-p2ch-c2c3-4xm5 (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/wintercms/winter/commit/353b23804dee2acf49fca996c72637040446824f (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/wintercms/winter/releases/tag/v1.2.14 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/wintercms/winter/commit/353b23804dee2acf49fca996c72637040446824f (security-advisories@github.com)

- https://github.com/wintercms/winter/releases/tag/v1.2.14 (security-advisories@github.com)

- https://github.com/wintercms/winter/security/advisories/GHSA-p2ch-c2c3-4xm5 (security-advisories@github.com)

- https://github.com/advisories/GHSA-p2ch-c2c3-4xm5 (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-p2ch-c2c3-4xm5 (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-125339; retrieved 2026-11-12; source updated 2026-11-12

- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-125339; retrieved 2026-11-11; source updated 2026-11-10

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-p2ch-c2c3-4xm5; retrieved 2026-11-10; source updated 2026-11-10

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-125339; retrieved 2026-11-12; source updated Not reported

Revision: 6bafa6c3dd3fd5e4096df1c47e21a7d3262da71847ffd4afdc015e5c06064d81

Canonical: https://y2.dev/cve/CVE-2026-125339

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