CVE-2026-123492 SiYuan before 3.8.9 Nil Pointer Dereference DoS via MCP resources/read
- Exploited in the wild
- Not known
- Fix
- None listed
What is CVE-2026-123492?
CVE-2026-123492 is a medium-severity vulnerability in siyuan-note siyuan, published on 6 Nov 2026.
Official 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.
Weakness: CWE-476
Which versions are affected by CVE-2026-123492?
How do I fix CVE-2026-123492?
No fix has been published for CVE-2026-123492 yet. Limit exposure of the affected software until one is available.
Is CVE-2026-123492 being exploited?
There is no known exploitation of CVE-2026-123492 in the wild and no public exploit code.
Sources
Also known as GHSA-2x3p-x74g-442x, GHSA-pxf5-vpcp-gg52.