---
title: "CVE-2026-116688: CKEditor 5 - Prototype Pollution"
description: "CKEditor 5 45.0.0 to 47.7.4 and 48.5.1 contains a prototype pollution caused by vulnerable es-toolkit processing style attribute values, letting attackers execute unauthorized JavaScript in the browser, exploit requires crafted editor content."
url: https://panop.io/threat-heartbeat/CVE-2026-116688/
---

# CVE-2026-116688 CKEditor 5 - Prototype Pollution

CKEditor 5 45.0.0 to 47.7.4 and 48.5.1 contains a prototype pollution caused by vulnerable es-toolkit processing style attribute values, letting attackers execute unauthorized JavaScript in the browser, exploit requires crafted editor content.

CVSS base score 8.1 /10

High

CISA KEV

Not listed

Public exploit

None known

Authentication

Required

EPSS

0.50% chance of exploitation in 30 days

[View the NVD record ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-116688)

## Details

Type

Prototype Pollution

Impact

Client Script Exec

CVSS vector

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

Published

27 October 2026

Updated

29 October 2026

Weakness

[CWE-79](https://cwe.mitre.org/data/definitions/79.html)

## Vendor fix

Update to versions 47.7.4 or 48.5.1 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

## References

- [https://nvd.nist.gov/vuln/detail/CVE-2026-116688](https://nvd.nist.gov/vuln/detail/CVE-2026-116688)
- [https://github.com/ckeditor/ckeditor5/commit/4d9c5bb34f63cd956d15ccafbe584e14280c86a0](https://github.com/ckeditor/ckeditor5/commit/4d9c5bb34f63cd956d15ccafbe584e14280c86a0)
- [https://github.com/ckeditor/ckeditor5/commit/a750e38635db6a18c5b11599c09f4fd702850423](https://github.com/ckeditor/ckeditor5/commit/a750e38635db6a18c5b11599c09f4fd702850423)
- [https://github.com/ckeditor/ckeditor5/releases/tag/v47.7.4](https://github.com/ckeditor/ckeditor5/releases/tag/v47.7.4)
- [https://github.com/ckeditor/ckeditor5/releases/tag/v48.5.1](https://github.com/ckeditor/ckeditor5/releases/tag/v48.5.1)
- [https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-rh54-vffm-5fvp](https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-rh54-vffm-5fvp)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

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