Quick answers
- Is CVE-2026-103763 exploited in the wild?
- No. Junglewise Threat Intelligence has no report of CVE-2026-103763 being exploited in the wild.
- How severe is CVE-2026-103763?
- Medium severity, with a CVSS score of 5.8, published 2 October 2026.
- Which products and versions are affected?
- SiYuan before 3.8.5.
- Is there a fix for CVE-2026-103763?
- Yes: fixed in v3.8.5. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
- How is CVE-2026-103763 attacked?
- It is attacked over the network, in a software library.
- Am I affected by CVE-2026-103763?
- Check whether you run SiYuan at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.
How to fix
- Fixed in: v3.8.5
Technical details
The POST /api/notebook/getNotebookInfo endpoint performs only notebook-level visibility checks but fails to apply per-document authorization filtering before returning aggregate metadata. An attacker with read-only publish role (or no credentials in passwordless deployments) can obtain document count, total byte size, and modification timestamps for all documents in a publish-visible notebook, including those individually excluded from publishing. The vulnerability exists because the handler calls the raw box.GetInfo() routine which sums metadata across all documents without applying publish-access predicates, violating the invariant that read-only roles must not learn metadata about excluded documents.
Affected products
- SiYuan SiYuan before 3.8.5
Timeline
- 2026-09-17: disclosed
- 2026-10-02: advisory