CVE-2026-100638

HIGH CVSS 4.0: 8.3 EPSS 0.47%
Updated Sep 30, 2026
B3Log
Parameter Value
CVSS 8.3 (HIGH)
Affected Versions before 3.8.4
Fixed In 3.8.4
Type CWE-73 (External Control of File Name or Path)
Vendor B3Log
Public PoC No

SiYuan versions before v3.8.4 contain a path traversal vulnerability in the setNotebookIcon endpoint that allows authenticated administrators to create arbitrary directory trees and write files outside the workspace boundary. Attackers can supply directory traversal sequences in the notebook parameter to escape the workspace data directory and write conf.json files to arbitrary locations accessible by the kernel process.

Attack Parameters

Attack Vector
Network
Can be exploited remotely
Attack Complexity
Low
Easy to exploit
Attack Requirements
None
No additional conditions
Privileges Required
High
Admin privileges needed
User Interaction
None
No user interaction needed

Impact Assessment

Confidentiality
None
No data leak
Integrity
High
Complete data modification
Availability
Low
Partial disruption

CVSS Vector v4.0

Vulnerable Products 1

Configuration From (including) Up to (excluding)
B3log Siyuan
cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*
— 3.8.4