PT-2026-6318 · Siyuan · Siyuan

Thxtech · Published 2026-01-29 · Updated 2026-02-04 · CVE-2026-25539

Positive Technologies (AI Summary)

CVSS v3.1

9.1

Critical

Base vector

AV:N/AC:L/PR:H/UI:N/S:C/C:H/I:H/A:H

Name of the Vulnerable Software and Affected Versions SiYuan versions prior to 3.5.5

Description SiYuan is a personal knowledge management system. The /api/file/copyFile endpoint does not validate the dest parameter. This allows authenticated users to write files to arbitrary locations on the filesystem, potentially leading to Remote Code Execution (RCE) by writing to sensitive locations such as cron jobs, SSH authorized keys, or shell configuration files.

Recommendations Update to version 3.5.5 or later.

Exploit

Fix

Path traversal

Weakness Enumeration

CWE-22

Related Identifiers

CVE-2026-25539

GHSA-C4JR-5Q7W-F6R9

GO-2026-4387

Affected Products

Siyuan

References · 9

• 🔥 https://github.com/siyuan-note/siyuan/security/advisories/GHSA-c4jr-5q7w-f6r9 · Exploit
• 🔥 https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/25xxx/CVE-2026-25539.json · Exploit
• https://github.com/siyuan-note/siyuan/commit/d7f790755edf8c78d2b4176171e5a0cdcd720feb · Patch
• https://osv.dev/vulnerability/GHSA-c4jr-5q7w-f6r9 · Vendor Advisory
• https://nvd.nist.gov/vuln/detail/CVE-2026-25539 · Security Note
• https://osv.dev/vulnerability/CVE-2026-25539 · Vendor Advisory
• https://osv.dev/vulnerability/GO-2026-4387 · Vendor Advisory
• https://github.com/siyuan-note/siyuan · Note
• https://twitter.com/CVEnew/status/2019182747772919998 · Twitter Post