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Medium

Security advisory

Type: advisorySources: OSVCVE: CVE-2020-26239

Scratch Addons is a WebExtension that supports both Chrome and Firefox. Scratch Addons before version 1.3.2 is vulnerable to DOM-based XSS. If the victim visited a specific website, the More Links addon of the Scratch Addons extension used incorrect regular expression which caused the HTML-escaped values to be unescaped, leading to XSS. Scratch Addons version 1.3.2 fixes the bug. The extension will be automatically updated by the browser. More Links addon can be disabled via the option of the extension.

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2020-26239
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 11:08 UTC · Revision 1

Source evidence

CVE-2020-26239

core-osv · Original source

Published 23 Nov 2020, 19:15 UTC

Scratch Addons is a WebExtension that supports both Chrome and Firefox. Scratch Addons before version 1.3.2 is vulnerable to DOM-based XSS. If the victim visited a specific website, the More Links addon of the Scratch Addons extension used incorrect regular expression which caused the HTML-escaped values to be unescaped, leading to XSS. Scratch Addons version 1.3.2 fixes the bug. The extension will be automatically updated by the browser. More Links addon can be disabled via the option of the extension.

osv:CVE-2020-26239
Complete source record
{
  "id": "5de49eeeef7d73eddf42b88c080df2621c8e8ea9b7e126f58b36d11bf03d77c9",
  "url": "https://osv.dev/vulnerability/CVE-2020-26239",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "CVE-2020-26239",
    "summary": "Scratch Addons is a WebExtension that supports both Chrome and Firefox. Scratch Addons before version 1.3.2 is vulnerable to DOM-based XSS. If the victim visited a specific website, the More Links addon of the Scratch Addons extension used incorrect regular expression which caused the HTML-escaped values to be unescaped, leading to XSS. Scratch Addons version 1.3.2 fixes the bug. The extension will be automatically updated by the browser. More Links addon can be disabled via the option of the extension.",
    "evidence": "osv:CVE-2020-26239",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2020-26239",
      "aliases": [
        "CVE-2020-26239",
        "GHSA-6qfq-px3r-xj4p"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:L/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/scratchaddons/scratchaddons",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "7868b54f15b7262ae50b1cafdc4e42966abbb098"
                },
                {
                  "fixed": "b9a52d6532c8514254c7cc1d8e18710dbedc41ff"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:scratchaddons:scratch_addons:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.3.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "b9a52d6532c8514254c7cc1d8e18710dbedc41ff"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "7868b54f15b7262ae50b1cafdc4e42966abbb098"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.3.2"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.3.1",
            "v1.3.0",
            "v1.2.1",
            "v1.2.0",
            "v1.1.1",
            "v1.1.0",
            "v1.0.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2020-26239.json"
          }
        }
      ],
      "modified": "2026-10-20T10:52:56.518745994Z",
      "provider": "osv",
      "references": [
        "https://github.com/ScratchAddons/ScratchAddons/blob/a471893df403f86c9182970678175d4772a0690c/addons/more-links/userscript.js#L15",
        "https://github.com/ScratchAddons/ScratchAddons/releases/tag/v1.3.2",
        "https://github.com/ScratchAddons/ScratchAddons/commit/b9a52d6532c8514254c7cc1d8e18710dbedc41ff",
        "https://github.com/ScratchAddons/ScratchAddons/security/advisories/GHSA-6qfq-px3r-xj4p"
      ],
      "provider_metadata": {}
    },
    "related_cves": [
      {
        "value": "CVE-2020-26239",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 384070,
  "published_at": "2020-11-23T19:15:11.117+00:00"
}