CVE-2026-87809CWE-639

CVE-2026-87809

Medium · published September 9, 2026

CVSS v3.1
6.5
EPSS
0%
Percentile
27.8
In the wild
Unconfirmed
What it is

Siyuan before v3.8.2 fails to apply publish-access filtering to embedded blocks before rendering in the /api/export/preview and /api/lute/copyStdMarkdown endpoints. Attackers with reader access can retrieve the full rendered content of private, hidden, or publish-disabled blocks by accessing public documents containing embed queries that select those blocks.

The record
Technical detail
CVSS v3.1
6.5 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
CVSS v4.0
7.1 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:N/VA:N/SC:N/SI:N/SA:N
EPSS
0.00354 · 27.8th percentile
Weakness
CWE-639 · Authorization Bypass Through User-Controlled Key
Published
2026-09-09T16:17Z
References (2)
https://github.com/siyuan-note/siyuan/security/advisories/GHSA-8wx4-fvqw-f5f8 · [email protected]https://www.vulncheck.com/advisories/siyuan-before-3.8.2-information-disclosure-via-export-preview · [email protected]
EPSS history
Timeline
  • 11 SEP 03:19Z
    EPSS moved — → 0%
    epss
  • 09 SEP 11:20Z
    Siyuan before v3.8.2 Information Disclosure via Export Preview
    cvelistv5