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.
Metrics
Affected Vendors & Products
References
History
Wed, 01 Jul 2026 15:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Title | Open VSX Registry Serves Unsecured HTML Payloads Leading to Session Token Theft |
Wed, 01 Jul 2026 13:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
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Wed, 01 Jul 2026 11:45:00 +0000
| Type | Values Removed | Values Added |
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| Description | 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. | |
| Weaknesses | CWE-79 | |
| References |
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| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: eclipse
Published:
Updated: 2026-07-01T12:19:20.920Z
Reserved: 2026-06-25T09:14:56.817Z
Link: CVE-2026-13323
Updated: 2026-07-01T12:12:58.749Z
No data.
No data.
OpenCVE Enrichment
Updated: 2026-07-01T15:00:06Z