Information disclosure in Siyuan-Note Siyuan
CVE-2026-87810
Siyuan before v3.8.2 contains an information disclosure vulnerability in the POST /api/search/fullTextSearchBlock endpoint that filters private blocks from results but returns unfiltered match counts. Unauthenticated publish-mode readers can submit arbitrary search terms to learn whether matching content exists in hidden or unpublished documents and determine the number of matching blocks and pages.
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.003 (26.6th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 27th percentile — 26.6% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.003 · newest: 0.003 · change: 0.000
Affected products
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-g45v-hxvm-wccj (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-3.8.2-information-disclosure-via-ful… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-87810?
- CVE-2026-87810 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Information Disclosure. CVSS score: 5.3/10. Published 2026-09-09.
- How severe is CVE-2026-87810?
- Medium severity. CVSS v3 base score is 5.3 out of 10.