Mastodon vulnerable to Stored XSS through the translation feature
Mastodon is a free, open-source social network server based on ActivityPub. In versions on the 4.x branch prior to versions 4.0.10, 4.2.8, and 4.2.0-rc2, under certain conditions, attackers can abuse the translation feature to bypass the server-side HTML sanitization, allowing unescaped HTML to execute in the browser. The impact is limited thanks to Mastodon's strict Content Security Policy, blocking inline scripts, etc. However a CSP bypass or loophole could be exploited to execute malicious XSS. Furthermore, it requires user interaction, as this can only occur upon clicking the “Translate” button on a malicious post. Versions 4.0.10, 4.2.8, and 4.2.0-rc2 contain a patch for this issue.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2023-42452
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 5 Nov 2026, 01:03 UTC · Revision 1
Source evidence
Mastodon vulnerable to Stored XSS through the translation feature
core-osv · Original sourcePublished 19 Sept 2023, 15:58 UTC
Mastodon is a free, open-source social network server based on ActivityPub. In versions on the 4.x branch prior to versions 4.0.10, 4.2.8, and 4.2.0-rc2, under certain conditions, attackers can abuse the translation feature to bypass the server-side HTML sanitization, allowing unescaped HTML to execute in the browser. The impact is limited thanks to Mastodon's strict Content Security Policy, blocking inline scripts, etc. However a CSP bypass or loophole could be exploited to execute malicious XSS. Furthermore, it requires user interaction, as this can only occur upon clicking the “Translate” button on a malicious post. Versions 4.0.10, 4.2.8, and 4.2.0-rc2 contain a patch for this issue.
osv:CVE-2023-42452
Complete source record
{
"id": "8b593b70acf546974272da3c1b7c362cd45cfe28442061b5bf2f069d12016551",
"url": "https://osv.dev/vulnerability/CVE-2023-42452",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "Mastodon vulnerable to Stored XSS through the translation feature",
"summary": "Mastodon is a free, open-source social network server based on ActivityPub. In versions on the 4.x branch prior to versions 4.0.10, 4.2.8, and 4.2.0-rc2, under certain conditions, attackers can abuse the translation feature to bypass the server-side HTML sanitization, allowing unescaped HTML to execute in the browser. The impact is limited thanks to Mastodon's strict Content Security Policy, blocking inline scripts, etc. However a CSP bypass or loophole could be exploited to execute malicious XSS. Furthermore, it requires user interaction, as this can only occur upon clicking the “Translate” button on a malicious post. Versions 4.0.10, 4.2.8, and 4.2.0-rc2 contain a patch for this issue.",
"evidence": "osv:CVE-2023-42452",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2023-42452",
"aliases": [
"BIT-mastodon-2023-42452",
"CVE-2023-42452",
"GHSA-2693-xr3m-jhqr"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/mastodon/mastodon",
"type": "GIT",
"events": [
{
"introduced": "fb389bd73c8a4bc2924496f6041c8eee27572d21"
},
{
"fixed": "3d8ae6ab739ab1222546923c8df703260285fbc3"
},
{
"introduced": "61c5dfb9295ea66c376c452a7ef7379e8c562416"
},
{
"fixed": "46bd58f74d11591a0180319285b0c79b2212ef69"
},
{
"introduced": "dab54ccbba3721382241725bb1c1159d24b5aab2"
},
{
"fixed": "ff32475f5f4a84ebf9619e7eef5bf8b4c075d0e2"
}
],
"database_specific": {
"extracted_events": [
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.0.10"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "4.1.0"
},
{
"fixed": "4.1.8"
}
],
"source": "CPE_RANGE"
},
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta1:*:*:*:*:*:*",
"range": [
{
"introduced": "4.2.0-beta1"
},
{
"last_affected": "4.2.0-beta1"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta2:*:*:*:*:*:*",
"range": [
{
"introduced": "4.2.0-beta2"
},
{
"last_affected": "4.2.0-beta2"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:4.2.0:beta3:*:*:*:*:*:*",
"range": [
{
"introduced": "4.2.0-beta3"
},
{
"last_affected": "4.2.0-beta3"
}
],
"source": "CPE_STRING"
},
{
"cpe": "cpe:2.3:a:joinmastodon:mastodon:4.2.0:rc1:*:*:*:*:*:*",
"range": [
{
"introduced": "4.2.0-rc1"
},
{
"last_affected": "4.2.0-rc1"
}
],
"source": "CPE_STRING"
},
{
"range": [
{
"fixed": "ff32475f5f4a84ebf9619e7eef5bf8b4c075d0e2"
}
],
"source": "REFERENCES_COMMIT"
}
]
}
}
],
"versions": [
"4.2.0-beta1",
"4.2.0-beta2",
"4.2.0-beta3",
"4.2.0-rc1",
"v4.2.0-rc1",
"v4.1.7",
"v4.0.9",
"v4.2.0-beta3",
"v4.0.8",
"v4.1.6",
"v4.2.0-beta2",
"v4.2.0-beta1",
"v4.0.7",
"v4.1.5",
"v4.0.6",
"v4.1.4",
"v4.1.3",
"v4.0.5",
"v4.0.4",
"v4.1.2",
"v4.1.1",
"v4.0.3",
"v4.0.2",
"v4.1.0",
"v4.0.1",
"v4.0.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2023-42452.json"
}
}
],
"modified": "2026-10-28T02:30:41.423885219Z",
"provider": "osv",
"references": [
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/42xxx/CVE-2023-42452.json",
"https://github.com/mastodon/mastodon/security/advisories/GHSA-2693-xr3m-jhqr",
"https://nvd.nist.gov/vuln/detail/CVE-2023-42452",
"https://github.com/mastodon/mastodon/commit/ff32475f5f4a84ebf9619e7eef5bf8b4c075d0e2"
],
"provider_metadata": {
"cwe_ids": [
"CWE-79"
],
"cna_assigner": "GitHub_M",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2023/42xxx/CVE-2023-42452.json"
}
},
"related_cves": [
{
"value": "CVE-2023-42452",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 508886,
"published_at": "2023-09-19T15:58:44.559+00:00"
}