# CVE-2026-116687: CKEditor: Cross-site scripting (XSS) in the engine package

Status: published. Published: 2026-10-27. Updated: 2026-11-03.

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. From 29.0.0 until 47.7.4 and 48.5.1, specially crafted markup can trigger cross-site scripting when General HTML Support is enabled and specifically configured to allow object content. Processing that content can execute attacker-controlled JavaScript in a browser context isolated from the origin of the application embedding the editor. This issue is fixed in versions 47.7.4 and 48.5.1.

## Remediation

- fix: ckeditor5 (npm): OSV reports a fixed version 47.7.4. Check the advisory for supported release branches. (source: OSV GHSA-v6mg-96c6-gmpq) — https://github.com/advisories/GHSA-v6mg-96c6-gmpq
- fix: @ckeditor/ckeditor5-engine (npm): OSV reports a fixed version 47.7.4. Check the advisory for supported release branches. (source: OSV GHSA-v6mg-96c6-gmpq) — https://github.com/advisories/GHSA-v6mg-96c6-gmpq
- fix: ckeditor5 (npm): OSV reports a fixed version 48.5.1. Check the advisory for supported release branches. (source: OSV GHSA-v6mg-96c6-gmpq) — https://github.com/advisories/GHSA-v6mg-96c6-gmpq
- fix: @ckeditor/ckeditor5-engine (npm): OSV reports a fixed version 48.5.1. Check the advisory for supported release branches. (source: OSV GHSA-v6mg-96c6-gmpq) — https://github.com/advisories/GHSA-v6mg-96c6-gmpq

## Affected products and versions

- ckeditor / ckeditor5: >= 29.0.0, < 47.7.4 (affected); >= 48.0.0, < 48.5.1 (affected). Source: CNA: GitHub_M
-  / ckeditor5 (ckeditor5): ≥ 29.0.0; < 47.7.4 (affected, semver); OSV events: introduced 29.0.0; fixed 47.7.4. Source: OSV GHSA-v6mg-96c6-gmpq
-  / @ckeditor/ckeditor5-engine (@ckeditor/ckeditor5-engine): ≥ 29.0.0; < 47.7.4 (affected, semver); OSV events: introduced 29.0.0; fixed 47.7.4. Source: OSV GHSA-v6mg-96c6-gmpq
-  / ckeditor5 (ckeditor5): ≥ 48.0.0; < 48.5.1 (affected, semver); OSV events: introduced 48.0.0; fixed 48.5.1. Source: OSV GHSA-v6mg-96c6-gmpq
-  / @ckeditor/ckeditor5-engine (@ckeditor/ckeditor5-engine): ≥ 48.0.0; < 48.5.1 (affected, semver); OSV events: introduced 48.0.0; fixed 48.5.1. Source: OSV GHSA-v6mg-96c6-gmpq

## Severity and prioritization

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

- CISA KEV: No listing in collected sources

- EPSS: 0.25% as of 2026-11-02; percentile 16.77%

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

- Weaknesses: CWE-79

## Exploit evidence

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

## References

- https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-v6mg-96c6-gmpq (CNA: GitHub_M; x_refsource_CONFIRM)

- https://github.com/ckeditor/ckeditor5/commit/4d9c5bb34f63cd956d15ccafbe584e14280c86a0 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/ckeditor/ckeditor5/commit/a750e38635db6a18c5b11599c09f4fd702850423 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/ckeditor/ckeditor5/releases/tag/v47.7.4 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/ckeditor/ckeditor5/releases/tag/v48.5.1 (CNA: GitHub_M; x_refsource_MISC)

- https://github.com/advisories/GHSA-v6mg-96c6-gmpq (OSV / GitHub Security Advisories; advisory)

- https://osv.dev/vulnerability/GHSA-v6mg-96c6-gmpq (OSV / GitHub Security Advisories; osv)

## Provenance

- CNA: GitHub_M: https://www.cve.org/CVERecord?id=CVE-2026-116687; retrieved 2026-11-03; source updated 2026-11-03

- OSV / GitHub Security Advisories: https://osv.dev/vulnerability/GHSA-v6mg-96c6-gmpq; retrieved 2026-11-03; source updated 2026-10-27

- FIRST EPSS: https://api.first.org/data/v1/epss?cve=CVE-2026-116687; retrieved 2026-11-03; source updated Not reported

Revision: 63658b7bab38e769e5fb8ed2d2280ae99b2f66790326d8719d1c2e9ab92b02cc

Canonical: https://y2.dev/cve/CVE-2026-116687

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- x402: Pay per request without an account or API key. Omit Authorization, read the HTTP 402 PAYMENT-REQUIRED challenge, validate its current requirements, and retry with PAYMENT-SIGNATURE through an authorized payment client. These browser tools never make payments. Guide: https://y2.dev/docs/api/x402.

- OpenAPI: https://y2.dev/api/openapi.yaml. Agent access metadata: https://y2.dev/cve/agent.json.

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