Open VSX Bug Let Malicious VS Code Extensions Bypass Pre-Publish Security Checks

Open VSX’s pre-publish scanning pipeline contained a bug that misinterpreted scanner failures as “no scanners configured,” allowing a malicious VS Code extension to pass vetting and go live. The flaw, dubbed Open Sesame, could be triggered by flooding the publish endpoint to exhaust the database connection pool and was fixed in Open VSX 0.32.0 after responsible disclosure. #OpenSesame #OpenVSX

Keypoints

A single boolean return value caused scanner failures to be treated as “nothing to scan,” letting extensions pass.
The vulnerability, named Open Sesame, enabled malicious Visual Studio Code extensions to be published and activated.
An attacker could exhaust the database connection pool by flooding the publish endpoint, causing scan jobs to fail to enqueue.
The flaw could be exploited by any publisher with a free account and affected marketplaces using Open VSX, including Cursor and Windsurf.
Open VSX patched the issue in version 0.32.0 after disclosure on February 8, 2026, and developers are advised to avoid fail-open error handling.