CVE-2026-87815

HIGH CVSS 4.0: 8.4 EPSS 0.48%
Updated Sep 14, 2026
B3Log
Parameter Value
CVSS 8.4 (HIGH)
Affected Versions before 3.8.2
Fixed In 3.8.2
Type CWE-73 (External Control of File Name or Path)
Vendor B3Log
Public PoC No

SiYuan versions before v3.8.2 contain a path traversal vulnerability in the /api/riff/removeRiffDeck endpoint that fails to validate the deckID parameter. An authenticated administrator can supply path traversal sequences to delete arbitrary .deck and .cards files outside the workspace directory.

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
High
Complete denial of service

CVSS Vector v4.0

Vulnerable Products 1

Configuration From (including) Up to (excluding)
B3log Siyuan
cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*
— 3.8.2