CVE-2026-77086

CRITICAL CVSS 4.0: 9.4 EPSS 0.65%
Updated Aug 26, 2026
SiYuan
Parameter Value
CVSS 9.4 (CRITICAL)
Type CWE-22 (Path Traversal)
Vendor SiYuan
Public PoC No

SiYuan before v3.7.4 fails to validate the packageName parameter in Bazaar install and uninstall endpoints, allowing authenticated administrators to perform path traversal via directory traversal sequences. Attackers with admin access can write arbitrary files to any location via install operations or recursively delete directories via uninstall operations by supplying crafted packageName values.

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
High
Complete data leak
Integrity
High
Complete data modification
Availability
High
Complete denial of service

CVSS Vector v4.0

Weakness Type (CWE)