Medium 6.9

SiYuan before 3.8.9 Nil Pointer Dereference DoS via MCP resources/read

CVE-2026-123492 First seen on SecPulse Nov 7, 00:00

Affected packages

Ecosystem	Package	Affected → Fixed	Fixed
siyuan-note	siyuan-notesiyuan	< 3.8.9→ 3.8.9	3.8.9

Original description The description as published by the source.

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.

Source: CVE.org (CVE Program・cvelistV5) NVD GitHub Advisory

References

advisory github.com
advisory vulncheck.com
advisory nvd.nist.gov
advisory github.com
web github.com

Key facts

CVSS v3: Medium 4.9; CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
CVSS v4: Medium 6.9; CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N
Published: Nov 7, 2026
First seen on SecPulse: Nov 7, 00:00
GHSA: GHSA-2x3p-x74g-442x
CWE: CWE-476

NVD GitHub Advisory

Tags(click for explanation)

Attack Types

Denial of Service

CWE

CWE-476

All

Siyuan Note Siyuan

Detection sources

OSV.dev (Open Source Vulnerabilities)Nov 10, 19:31
NIST National Vulnerability DatabaseNov 10, 08:17
GitHub Security Advisories (Global)Nov 7, 00:31
CVE.org (CVE Program・cvelistV5)Nov 10, 07:45