PT-2026-54628 · Eclipse Foundation · Eclipse Open Vsx

Golan Myers · Published 2026-07-01 · Updated 2026-07-01 · CVE-2026-13323

NVD

CVSS v3.1

4.1

Medium

Base vector

AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:L/A:N

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.

Exploit

Fix

XSS

Weakness Enumeration

CWE-79

Related Identifiers

CVE-2026-13323

Affected Products

Eclipse Open Vsx

References · 3

• 🔥 https://gitlab.eclipse.org/security/vulnerability-reports/-/work_items/485 · Exploit
• https://nvd.nist.gov/vuln/detail/CVE-2026-13323 · Security Note
• https://github.com/eclipse-openvsx/openvsx/pull/1922 · Note