CVE-2026-123492
SiYuan before 3.8.9 contains a nil pointer dereference vulnerability in privateCacheMiddleware that allows authenticated attackers to crash the kernel by reading nonexistent MCP resources. Attackers with a valid API token can send a resources/read request in an initialized MCP session, causing a panic that terminates the kernel process and interrupts service.
Published:Nov 6, 2026
Last Modified:Nov 6, 2026
EPS:Nov 6, 2026
EPSS Score:
CVSS Score:4.9
Affected Products
Vendor
Product
Action
Vendor
B3log
Product
Siyuan
B3log
Siyuan
Vendor
Siyuan
Product
Siyuan
Siyuan
Siyuan
Exploits
No exploit reference
Common Weakness Enumeration
Common Attack Pattern Enumeration and Classification (CAPEC)
No CAPEC recorded yet
Related CVEs
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
