Cursor AI Extension Token Access Flaw Could Lead to Full Credential Compromise

Security researchers disclosed a CVSS 8.2 vulnerability in the Cursor development environment that allows any installed extension to query a predictable, unencrypted local SQLite database and exfiltrate plaintext API keys and session tokens. The flaw—caused by insecure credential storage and no isolation/sandboxing for extensions—enables stealthy credential theft with high potential impact (cloud and API abuse); Cursor had not released a patch as of April 2026 and users are advised to avoid untrusted extensions, rotate keys, and use external secure storage.