CVE-2026-72808: SiYuan missing authorization on getFileAnnotation endpoint

Executive brief

SiYuan is a personal knowledge management tool that supports storing PDFs with annotations (highlights and notes). The `/api/asset/getFileAnnotation` endpoint fails to enforce publish-access controls, allowing unauthorized users to read private PDF annotations from password-protected or unpublished documents. An attacker who knows an asset path can retrieve sensitive annotated content that should be restricted.

Technical details

SiYuan's `/api/asset/getFileAnnotation` API endpoint resolves annotation files (`.sya` files containing PDF highlights and notes) via `GetAssetAbsPathInBox` and returns their content without any publish-access verification. The endpoint is gated only by `CheckAuth`, which admits the publish `RoleReader` token and anonymous accounts when `Publish.Auth.Enable` is disabled. In contrast, the `/assets/*` route properly enforces publish-access controls, publish-ignore flags, and password checks before serving asset data. The missing boundary check allows attackers who know an asset path to bypass document-level access controls. The vulnerability is limited to non-encrypted assets; encrypted-box annotations are fail-closed. The fix requires applying the same publish-access filter that protects `/assets/*` to the `getFileAnnotation` endpoint.

Affected products

• SiYuan SiYuan < 0.0.0-20260723031702-509b35055940

Timeline

• 2026-09-03: disclosed: Advisory published to GitHub Advisory Database
• 2026-07-23: patched: Fix released in version 0.0.0-20260723031702-509b35055940

References

• https://api.github.com/users/Shirshakhtml
• https://github.com/Shirshakhtml
• https://api.github.com/users/Shirshakhtml/gists%7B/gist_id%7D
• https://api.github.com/users/Shirshakhtml/repos
• https://avatars.githubusercontent.com/u/75179984?v=4
• https://api.github.com/users/Shirshakhtml/events%7B/privacy%7D