CVE-2026-85579 SiYuan before v3.8.2 Information Disclosure via undoState
An authenticated reader can leak internal root IDs of private documents via the undoState API, exposing cross-document relationships.
- Exploited in the wild
- Not known
- Login needed
- Any signed-in user
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-85579?
CVE-2026-85579 is a medium-severity vulnerability in siyuan-note siyuan, published on 4 Sep 2026. Any signed-in user can exploit it over the network, with no action from the victim.
Official description
SiYuan is affected by an information disclosure vulnerability (confirmed in v3.8.1, fixed in v3.8.2) in the reader-accessible POST /api/transactions/undoState endpoint. The endpoint returns the peekMutatedRootIDs list from the global undo-log stack for a caller-supplied root ID without applying publish-access visibility filtering. An authenticated reader who knows the root ID of a visible document can obtain the internal root IDs of other documents (including private or unpublished ones) modified in the same cross-document transaction, disclosing internal identifiers and cross-document relationships. Document body contents are not directly exposed.
Weakness: CWE-639
Which versions are affected by CVE-2026-85579?
How do I fix CVE-2026-85579?
No fix has been published for CVE-2026-85579 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-85579 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-85579 exists.
Sources
Also known as GHSA-6gf8-q9ch-w732, GHSA-pf8f-99x6-h9q4.