Information disclosure in Siyuan-Note Siyuan
CVE-2026-82651
SiYuan before v3.8.1 does not apply the IsForbiddenAbsPath guard (introduced in GHSA-c8r8-95hg-mp34) to the /history/*path and /repo/diff/*path endpoints in kernel/server/serve.go. These routes require admin authentication but construct file paths independently, so an authenticated administrator can retrieve historical snapshots of sensitive files that the guard is meant to block, including data/.siyuan/publishAccess.json (plaintext publish-mode passwords) and files under data/templates/.
Vulnerability class: Information Disclosure
Published · last modified .
CVSS v3 metric
CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:H/I:N/A:N.
EPSS exploit prediction
EPSS: 0.005 (39.7th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 40th percentile — 39.7% 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: 0.005 · change: +0.002
Affected products
Weakness classification (CWE)
References
- github.com/siyuan-note/siyuan/security/advisories/GHSA-3cm4-ccvw-6xr6 (vendor-advisory)
- www.vulncheck.com/advisories/siyuan-before-3.8.1-missing-authorization-via-hist… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-82651?
- CVE-2026-82651 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under Information Disclosure. CVSS score: 4.9/10. Published 2026-08-30.
- How severe is CVE-2026-82651?
- Medium severity. CVSS v3 base score is 4.9 out of 10.