Actual vulnerabilities

Actual is a local-first personal finance tool. Prior to 26.7.0, Actual Sync Server's CORS proxy is intended to let authenticated users fetch resources only from repositories listed in the official plugin allowlist. When ACTUAL_GITHUB_TOKEN is configured, the proxy automatically attaches the server's GitHub token to GitHub requests. The GitHub API allowlist check uses a raw startsWith() prefix test for /repos/{owner}/{repo} without requiring a path boundary after the repository name. If an allowlisted public plugin repository is https://github.com/acme/plugin, the proxy also accepts GitHub API URLs. Those URLs are outside the allowlisted repository but still pass because their API path starts with /repos/acme/plugin. The proxy then forwards the request with the server's ACTUAL_GITHUB_TOKEN, allowing any authenticated Actual user to read private GitHub resources reachable by that token. Version 26.7.0 fixes the issue.

In Actual prior to 26.6.0, CSV export functions do not neutralize formula prefixes, allowing injection of malicious formulas (e.g., starting with =, +, -) into CSV files. When opened in Excel, LibreOffice Calc, or Google Sheets, these formulas execute, enabling transaction data exfiltration and manipulation of displayed values.

In Actual app in OpenID multi-user mode, disabling a user only blocks future OpenID login, but existing session tokens remain valid. The session validation does not check if the user is still enabled, allowing a disabled user to continue accessing authenticated endpoints.

In Actual up to 26.7.0, a missing authorization issue allows a shared user with user_access on a budget file to perform owner-only file management actions. A non-owner shared user can call endpoints like /delete-user-file, /reset-user-file, and /user-create-key because requireFileAccess treats ordinary shared access as sufficient for these operations.