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.
Published: 2026-11-06
Score: 6.9 Medium
EPSS: n/a
KEV: No
AI Analysis

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Remediation

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Tracking

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Advisories

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History

Fri, 06 Nov 2026 15:15:00 +0000

Type Values Removed Values Added
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.
Title SiYuan before 3.8.9 Nil Pointer Dereference DoS via MCP resources/read
First Time appeared B3log
B3log siyuan
Weaknesses CWE-476
CPEs cpe:2.3:a:b3log:siyuan:*:*:*:*:*:*:*:*
Vendors & Products B3log
B3log siyuan
References
Metrics cvssV3_1

{'score': 4.9, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'}

cvssV4_0

{'score': 6.9, 'vector': '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'}

Subscriptions

B3log Siyuan
cve-icon MITRE

Status: PUBLISHED

Assigner: VulnCheck

Published:

Updated: 2026-11-06T15:00:52.853Z

Reserved: 2026-11-06T00:44:37.659Z

Link: CVE-2026-123492

cve-icon Vulnrichment

No data.

cve-icon NVD

Status : Deferred

Published: 2026-11-06T15:17:18.830

Modified: 2026-11-06T15:17:18.963

Link: CVE-2026-123492

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

No data.

Weaknesses