CVE-2026-85579

What it is

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who knows the root ID of a visible document can obtain the internal root IDs of other documents (including private or unpublished ones) modified in the same cross-document transaction, disclosing internal identifiers and cross-document relationships.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.

At a glance

Exploitability

Can be exploited over the network with a low-privilege account. Limited direct impact.

Exploit odds

0.3% chance of exploitation in the next 30 days (EPSS).

Fix

A patch, advisory or fixed version is referenced. Upgrade or apply it.

Timeline

1. 2026-09-04 12:17 UTC PublishedDisclosed publicly on CVE.org and NVD
2. 2026-09-08 20:05 UTC Last updatedMost recent change to the record

Details

Published

2026-09-04 12:17 UTC

Last modified

2026-09-08 20:05 UTC

Exploit probability

0.3% · EPSS, next 30 days

Weakness

CWE-639 · Insecure direct object reference

Record status

Deferred

Attack profile CVSS 4.0 · 5.3

Attack vector

Network

Complexity

Low

Attack requirements

None

Privileges needed

Low

User interaction

None

Confidentiality

Low

Integrity

None

Availability

None