Vulnerability record · CVE-2026-13323 · published 1 July 2026
CVE-2026-13323: Eclipse open vsx cross-site scripting vulnerability
Eclipse · Open Vsx
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.
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.
CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:N
Affected products
1 vulnerable configurations from NVD's CPE data, grouped by vendor and product.
References
| Link | Tags |
|---|---|
| https://github.com/eclipse-openvsx/openvsx/pull/1922 | Issue TrackingPatch |
| https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/485 | ExploitIssue TrackingVendor Advisory |
| https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/485 | ExploitIssue TrackingVendor Advisory |
Track CVE-2026-13323 inside VULONE
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Related vulnerabilities
Same products first, then exploited flaws of the same weakness class.
Source: NIST National Vulnerability Database (record CVE-2026-13323), CISA KEV, FIRST EPSS (scores of 2026-09-27). This page is refreshed as NVD updates the record.
