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.

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publish-mode readers can submit arbitrary search terms to learn whether matching content exists in hidden or unpublished documents and determine the number of matching blocks and pages.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

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.

Affected products

Siyuan-note Siyuan

Weakness classification (CWE)

CWE-200 — Information Disclosure

References

disclosure@vulncheck.com (vendor-advisory)
disclosure@vulncheck.com (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.