What is CVE-2026-123492?

CVE-2026-123492 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under NULL Pointer Dereference. CVSS score: 4.9/10. Published 2026-11-06.

How severe is CVE-2026-123492?

Medium severity. CVSS v3 base score is 4.9 out of 10.

NULL pointer dereference in Siyuan-Note Siyuan

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 2026-11-06 · last modified 2026-11-06.

CVSS v3 metric

CVSS v3 base score 4.9 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Siyuan-Note Siyuan

Weakness classification (CWE)

CWE-476 — NULL Pointer Dereference

References

github.com/siyuan-note/siyuan/security/advisories/GHSA-2x3p-x74g-442x (vendor-advisory)
www.vulncheck.com/advisories/siyuan-before-3.8.9-nil-pointer-dereference-dos-vi… (third-party-advisory)

Frequently asked questions

What is CVE-2026-123492?: CVE-2026-123492 is a medium-severity vulnerability in Siyuan-Note Siyuan, classified under NULL Pointer Dereference. CVSS score: 4.9/10. Published 2026-11-06.
How severe is CVE-2026-123492?: Medium severity. CVSS v3 base score is 4.9 out of 10.