Vulnerability-Lookup

GHSA-RH54-VFFM-5FVP

Vulnerability from github – Published: 2026-10-27 21:05 – Updated: 2026-10-27 21:05

Summary

CKEditor: Cross-site scripting (XSS) in the engine package

Details

Impact

A Cross-Site Scripting (XSS) vulnerability has been discovered in the CKEditor 5 engine. This vulnerability is caused by a prototype pollution issue in the es-toolkit library used in the CKEditor 5 codebase. This vulnerability could lead to unauthorized JavaScript code execution when the editor processes incoming style attribute values.

The underlying issue has been patched by the library maintainers, and the fix has been incorporated into CKEditor 5.

Patches

The problem has been recognized and patched. The fix will be available in version 48.5.1 (and above) and 47.7.4 (LTS).

For more information

Email us at security@cksource.com if you have any questions or comments about this advisory.

Severity

8.1 (High)


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

Show details on source website

JSON

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{
  "affected": [
    {
      "package": {
        "ecosystem": "npm",
        "name": "ckeditor5"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "45.0.0"
            },
            {
              "fixed": "47.7.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@ckeditor/ckeditor5-engine"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "45.0.0"
            },
            {
              "fixed": "47.7.4"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "ckeditor5"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "48.0.0"
            },
            {
              "fixed": "48.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    },
    {
      "package": {
        "ecosystem": "npm",
        "name": "@ckeditor/ckeditor5-engine"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "48.0.0"
            },
            {
              "fixed": "48.5.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-116688"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-79"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-10-27T21:05:06Z",
    "nvd_published_at": null,
    "severity": "HIGH"
  },
  "details": "### Impact\nA Cross-Site Scripting (XSS) vulnerability has been discovered in the CKEditor 5 engine. This vulnerability is caused by a prototype pollution issue in the `es-toolkit` library used in the CKEditor 5 codebase. This vulnerability could lead to unauthorized JavaScript code execution when the editor processes incoming `style` attribute values.\n\nThe underlying issue has been patched by the library maintainers, and the fix has been incorporated into CKEditor 5.\n\n### Patches\nThe problem has been recognized and patched. The fix will be available in version `48.5.1` (and above) and `47.7.4` (LTS).\n\n### For more information\nEmail us at [security@cksource.com](mailto:security@cksource.com) if you have any questions or comments about this advisory.",
  "id": "GHSA-rh54-vffm-5fvp",
  "modified": "2026-10-27T21:05:06Z",
  "published": "2026-10-27T21:05:06Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-rh54-vffm-5fvp"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ckeditor/ckeditor5/commit/4d9c5bb34f63cd956d15ccafbe584e14280c86a0"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ckeditor/ckeditor5/commit/a750e38635db6a18c5b11599c09f4fd702850423"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/ckeditor/ckeditor5"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ckeditor/ckeditor5/releases/tag/v47.7.4"
    },
    {
      "type": "WEB",
      "url": "https://github.com/ckeditor/ckeditor5/releases/tag/v48.5.1"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "CKEditor: Cross-site scripting (XSS) in the engine package"
}

CVE-2026-116688 (GCVE-0-2026-116688)

Vulnerability from cvelistv5 – Published: 2026-10-27 19:36 – Updated: 2026-10-27 19:36

Title

CKEditor: Cross-site scripting (XSS) in the engine package

Summary

CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. From 45.0.0 until 47.7.4 and 48.5.1, the engine uses a vulnerable es-toolkit version whose prototype-pollution behavior can be reached while CKEditor processes incoming style attribute values. Crafted editor content can thereby cause unauthorized JavaScript execution in the browser. This issue is fixed in versions 47.7.4 and 48.5.1.

Severity

8.1 (High)


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

CWE

CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7926 records in the last 180 days details

References

5 references

URL	Tags
https://github.com/ckeditor/ckeditor5/security/ad…	x_refsource_CONFIRM
https://github.com/ckeditor/ckeditor5/commit/4d9c…	x_refsource_MISC
https://github.com/ckeditor/ckeditor5/commit/a750…	x_refsource_MISC
https://github.com/ckeditor/ckeditor5/releases/ta…	x_refsource_MISC
https://github.com/ckeditor/ckeditor5/releases/ta…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
ckeditor	ckeditor5	Affected: >= 45.0.0, < 47.7.4 Affected: >= 48.0.0, < 48.5.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "product": "ckeditor5",
          "vendor": "ckeditor",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 45.0.0, \u003c 47.7.4"
            },
            {
              "status": "affected",
              "version": "\u003e= 48.0.0, \u003c 48.5.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "CKEditor 5 is a modern JavaScript rich-text editor with an MVC architecture. From 45.0.0 until 47.7.4 and 48.5.1, the engine uses a vulnerable es-toolkit version whose prototype-pollution behavior can be reached while CKEditor processes incoming style attribute values. Crafted editor content can thereby cause unauthorized JavaScript execution in the browser. This issue is fixed in versions 47.7.4 and 48.5.1."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 8.1,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-27T19:36:28.906Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-rh54-vffm-5fvp",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/ckeditor/ckeditor5/security/advisories/GHSA-rh54-vffm-5fvp"
        },
        {
          "name": "https://github.com/ckeditor/ckeditor5/commit/4d9c5bb34f63cd956d15ccafbe584e14280c86a0",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/ckeditor/ckeditor5/commit/4d9c5bb34f63cd956d15ccafbe584e14280c86a0"
        },
        {
          "name": "https://github.com/ckeditor/ckeditor5/commit/a750e38635db6a18c5b11599c09f4fd702850423",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/ckeditor/ckeditor5/commit/a750e38635db6a18c5b11599c09f4fd702850423"
        },
        {
          "name": "https://github.com/ckeditor/ckeditor5/releases/tag/v47.7.4",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/ckeditor/ckeditor5/releases/tag/v47.7.4"
        },
        {
          "name": "https://github.com/ckeditor/ckeditor5/releases/tag/v48.5.1",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/ckeditor/ckeditor5/releases/tag/v48.5.1"
        }
      ],
      "source": {
        "advisory": "GHSA-rh54-vffm-5fvp",
        "discovery": "UNKNOWN"
      },
      "title": "CKEditor: Cross-site scripting (XSS) in the engine package"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-116688",
    "datePublished": "2026-10-27T19:36:28.906Z",
    "dateReserved": "2026-10-26T20:00:59.830Z",
    "dateUpdated": "2026-10-27T19:36:28.906Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

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