Security advisory
In Open VSX Registry before 1.0.2, the /vscode/unpkg/ endpoint serves user-supplied HTML files with Content-Type: text/html and without a Content-Security-Policy or Content-Disposition: attachment response header. An unauthenticated attacker can register a publisher account, upload a VSIX containing a crafted HTML payload, and induce an authenticated user to visit the resulting URL. The browser renders the file inline in the open-vsx.org origin context, enabling session token exfiltration, persistent Personal Access Token (PAT) generation, and unauthorized publication of malicious extension versions. Because Open VSX extensions are distributed to VS Code, VSCodium, Cursor, Windsurf, and compatible editors, a compromised extension update constitutes a supply chain attack against all downstream users.
- Products
- Not specified
- Affected versions
- Not specified
- Fixed versions
- Not specified
- CVEs
- CVE-2026-13323
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 7 Nov 2026, 10:39 UTC · Revision 1
Source evidence
In Open VSX Registry before 1.0.2, the /vscode/unpkg/ endpoint serves user-supplied HTML files with Content-Type: text/html and without a Content-Security-Policy or Content-Disposition: attachment response header. An unauthenticated attacker can register a publisher account, upload a VSIX containing a crafted HTML payload, and induce an authenticated user to visit the resulting URL. The browser renders the file inline in the open-vsx.org origin context, enabling session token exfiltration, persistent Personal Access Token (PAT) generation, and unauthorized publication of malicious extension versions. Because Open VSX extensions are distributed to VS Code, VSCodium, Cursor, Windsurf, and compatible editors, a compromised extension update constitutes a supply chain attack against all downstream users.
osv:CVE-2026-13323
Complete source record
{
"id": "55c1df569a708a04f354a6944262bdd5196c16f60adc0c6fe3e304015595501d",
"url": "https://osv.dev/vulnerability/CVE-2026-13323",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "CVE-2026-13323",
"summary": "In Open VSX Registry before 1.0.2, the /vscode/unpkg/ endpoint serves user-supplied HTML files with Content-Type: text/html and without a Content-Security-Policy or Content-Disposition: attachment response header. An unauthenticated attacker can register a publisher account, upload a VSIX containing a crafted HTML payload, and induce an authenticated user to visit the resulting URL. The browser renders the file inline in the open-vsx.org origin context, enabling session token exfiltration, persistent Personal Access Token (PAT) generation, and unauthorized publication of malicious extension versions. Because Open VSX extensions are distributed to VS Code, VSCodium, Cursor, Windsurf, and compatible editors, a compromised extension update constitutes a supply chain attack against all downstream users.",
"evidence": "osv:CVE-2026-13323",
"products": [],
"severity": "medium",
"structured": {
"id": "CVE-2026-13323",
"aliases": [
"CVE-2026-13323"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N"
}
],
"affected": [
{
"ranges": [
{
"repo": "https://github.com/eclipse-openvsx/openvsx",
"type": "GIT",
"events": [
{
"introduced": "8ab80e417515a59f80ff9db6a39fab302819ef9f"
},
{
"fixed": "9491f32a6d459a4d499c5028d37c0d0386771e9f"
}
],
"database_specific": {
"extracted_events": [
{
"range": [
{
"introduced": "0.1.0"
},
{
"fixed": "1.0.2"
}
],
"source": "AFFECTED_FIELD",
"strategy": "StandardRange"
},
{
"cpe": "cpe:2.3:a:eclipse:open_vsx:*:*:*:*:*:*:*:*",
"range": [
{
"introduced": "0"
},
{
"fixed": "1.0.2"
}
],
"source": "CPE_RANGE"
}
]
}
}
],
"versions": [
"cli-1.0.2",
"webui-1.0.1",
"v1.0.1",
"cli-1.0.1",
"webui-1.0.0",
"v1.0.0",
"cli-1.0.0",
"webui-0.20.4",
"v0.34.6",
"v0.34.5",
"webui-0.20.3",
"v0.34.4",
"cli-0.10.12",
"v0.34.3",
"v0.34.2",
"webui-0.20.2",
"webui-0.20.1",
"v0.34.1",
"webui-0.20.0",
"v0.34.0",
"cli-0.10.11",
"webui-0.19.1",
"v0.33.1",
"webui-0.19.0",
"v0.33.0",
"cli-0.10.10",
"v0.32.3",
"v0.32.2",
"v0.32.1",
"v0.32.0",
"webui-0.18.0",
"cli-0.10.9",
"v0.31.0",
"webui-0.17.1",
"cli-0.10.8",
"v0.30.0",
"v0.29.1",
"v0.29.0",
"v0.28.0",
"v0.27.0",
"v0.26.0",
"v0.25.0",
"v0.24.0",
"v0.23.5",
"v0.23.4",
"v0.23.3",
"v0.23.2",
"v0.23.1",
"v0.23.0",
"v0.22.2",
"v0.22.1",
"v0.22.0",
"v0.21.1",
"v0.21.0",
"v0.19.0",
"v0.20.0",
"v0.18.1",
"v0.18.0",
"v0.17.0",
"v0.16.4",
"v0.16.3",
"v0.16.2",
"v0.16.1",
"v0.16.0",
"v0.15.8",
"v0.15.7",
"v0.15.6",
"v0.15.5",
"v0.15.4",
"v0.15.3",
"v0.15.2",
"v0.15.1",
"v0.15.0",
"v0.14.6",
"v0.14.5",
"v0.14.4",
"v0.14.3",
"v0.14.2",
"v0.14.1",
"v0.14.0",
"v0.13.4",
"v0.13.3",
"v0.13.2",
"v0.13.1",
"v0.13.0",
"v0.12.0",
"v0.11.1",
"v0.11.0",
"v0.10.0",
"v0.9.7",
"v0.9.6",
"v0.9.5",
"v0.9.4",
"v0.9.3",
"v0.9.1",
"v0.9.0",
"v0.7.0",
"v0.6.0",
"cli-0.2.0",
"v0.1.0"
],
"database_specific": {
"source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-13323.json"
}
}
],
"modified": "2026-10-28T02:30:50.436911284Z",
"provider": "osv",
"references": [
"https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/485",
"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13323.json",
"https://nvd.nist.gov/vuln/detail/CVE-2026-13323",
"https://github.com/eclipse-openvsx/openvsx/pull/1922"
],
"provider_metadata": {
"cwe_ids": [
"CWE-79"
],
"cna_assigner": "eclipse",
"osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/13xxx/CVE-2026-13323.json"
}
},
"related_cves": [
{
"value": "CVE-2026-13323",
"evidence": "/id"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 519031,
"published_at": "2026-07-01T11:28:20.888+00:00"
}