CKEditor5 cross-site scripting vulnerability caused by the editor instance destroying process

Exploitation

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

CVSS

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

EPSS

• CVE-2022-31175: 0.88% estimated exploitation activity in the next 30 days; percentile 59.25 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Affected packages @ckeditor/ckeditor5-markdown-gfm @ckeditor/ckeditor5-html-support @ckeditor/ckeditor5-html-embed Impact A cross-site scripting vulnerability has been discovered affecting three optional CKEditor 5's packages. The vulnerability allowed to trigger a JavaScript code after fulfilling special conditions: a) Using one of the affected packages. In case of ckeditor5-html-support and ckeditor5-html-embed, additionally, it was required to use a configuration that allows unsafe markup inside the editor, b) Initializing the editor on an element and using an element other than <textarea as a base, c) Destroying the editor instance. The root cause of the issue was a mechanism responsible for updating the source element with the markup coming from the CKEditor 5 data pipeline after destroying the editor. This vulnerability might affect a small percent of integrators that depend on dynamic editor initialization/destroy and use Markdown, General HTML Support or HTML embed features.…

Published by the source

6 Aug 2022, 09:40 UTC

Last modified by the source

8 Nov 2023, 04:09 UTC

Source last checked

26 Oct 2026, 12:17 UTC

1. Revision 2 · amended · 26 Oct 2026

   Amended from ghsa record GHSA-42wq-rch8-6f6j

2. Revision 1 · created · 24 Oct 2026

   Published from osv record GHSA-42wq-rch8-6f6j

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# Patch Next advisory brief: CVE-2022-31175

Advisory: CKEditor5 cross-site scripting vulnerability caused by the editor instance destroying process
IDs: CVE-2022-31175, GHSA-42wq-rch8-6f6j
Record: https://patchnext.com/advisories/cve-2022-31175 (revision 2, source checked 26 Oct 2026, 12:17 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 5.8)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: @ckeditor/ckeditor5-markdown-gfm 35.0.1; @ckeditor/ckeditor5-html-embed 35.0.1; @ckeditor/ckeditor5-html-support 35.0.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- npm @ckeditor/ckeditor5-markdown-gfm: affected < 35.0.1; fixed in 35.0.1
- npm @ckeditor/ckeditor5-html-embed: affected < 35.0.1; fixed in 35.0.1
- npm @ckeditor/ckeditor5-html-support: affected < 35.0.1; fixed in 35.0.1

## Suggested inspection (read-only)
- `npm ls @ckeditor/ckeditor5-markdown-gfm --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @ckeditor/ckeditor5-html-embed --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.
- `npm ls @ckeditor/ckeditor5-html-support --all`: lists every installed copy and version, including transitive ones. Run in the project root after `npm ci`.

## 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 @ckeditor/ckeditor5-markdown-gfm, @ckeditor/ckeditor5-html-embed, @ckeditor/ckeditor5-html-support.
- 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-42wq-rch8-6f6j (OSV record GHSA-42wq-rch8-6f6j lists affected ranges: npm @ckeditor/ckeditor5-markdown-gfm >=0 =0 =0 <35.0.1 (fixed))
- Verified: https://github.com/advisories/GHSA-42wq-rch8-6f6j (GitHub-reviewed advisory GHSA-42wq-rch8-6f6j lists affected ranges: npm @ckeditor/ckeditor5-markdown-gfm >=0 =0 =0 <35.0.1)

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