GitBook said an attacker used AI agents on Nov. 2, 2026, to access some of its infrastructure credentials. Third-party integration tokens, Git Sync secrets, personal API tokens and questions submitted through GitBook Assistant may have been compromised. The company said it found no evidence of unauthorized changes to customer content.
GitBook said it blocked further access, closed the exploited vulnerabilities, rotated internal credentials and revoked customers’ API tokens. As of Nov. 3, it had restored its app, API and published documentation, though some services could still have limitations. It advised users to update third-party integration keys and secrets and reauthorize GitBook MCP Server connections.
