Security advisory
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
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"
}