CVE-2026-123492
MEDIUM
NVD
CVSS Score
4.9
Severity
MEDIUM
Published
Nov 06, 2026
Vendor
unknown
Description
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.