Winter: Reflected XSS through the search query parameter in the backend Table widget

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

4.5 · CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:U/C:N/I:H/A:N

EPSS

No dated EPSS signal available.

As published by the source; long descriptions are shortened.

Impact Affected versions of Winter CMS render the search query parameter without HTML encoding inside a <script type="text/template" block in the backend Table widget partial (modules/backend/widgets/table/partials/table.php): <script is an HTML raw-text context, so the surrounding value="…" attribute quoting is not a parser boundary. A literal </script in the query string terminates the template element early, and everything after it is parsed as ordinary markup in the backend document. Any backend page rendering a Table or DataTable widget is a sink. The value is read from the global request through the get() helper, which — unlike post() — is not restricted by HTTP method, so a plain top-level GET navigation is sufficient. The template is also emitted unconditionally by the partial, so widgets using the default searching: false configuration are equally affected. In Winter core the reachable route is the Editor Settings form (/backend/system/settings/update/winter/backend/editor),…

Published by the source

20 Aug 2026, 18:45 UTC

Last modified by the source

20 Aug 2026, 19:00 UTC

Source last checked

26 Oct 2026, 14:50 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-hq84-x37p-j6q5

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-hq84-x37p-j6q5

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# Patch Next advisory brief: GHSA-hq84-x37p-j6q5

Advisory: Winter: Reflected XSS through the search query parameter in the backend Table widget
IDs: GHSA-hq84-x37p-j6q5
Record: https://patchnext.com/advisories/ghsa-hq84-x37p-j6q5 (revision 2, source checked 26 Oct 2026, 14:50 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 4.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: winter/wn-backend-module 1.2.14. A vendor fix does not mean a deployment is fixed.

## Affected components
- Packagist winter/wn-backend-module: affected >= 1.0.420, <= 1.2.13; fixed in 1.2.14

## Suggested inspection (read-only)
- Packagist winter/wn-backend-module: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on winter/wn-backend-module.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://osv.dev/vulnerability/GHSA-hq84-x37p-j6q5 (OSV record GHSA-hq84-x37p-j6q5 lists affected ranges: Packagist winter/wn-backend-module >=1.0.420 <1.2.14 (fixed))
- Verified: https://github.com/advisories/GHSA-hq84-x37p-j6q5 (GitHub-reviewed advisory GHSA-hq84-x37p-j6q5 lists affected ranges: Packagist winter/wn-backend-module >=1.0.420 <=1.2.13)

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