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

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.

Affected products

Weakness classification (CWE)

References

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.