CVE-2026-123492 siyuan-note siyuan: NULL Pointer Dereference

6.9 mediumEPSS 0.3%

Medium (6.9) in siyuan-note siyuan. EPSS 0.3% estimated probability of exploitation activity in the next 30 days.

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Affected
Versions
References
Your exposure

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.

Severity

CVSS 4.0

6.9 medium

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

CVSS 3.1

4.9 medium

CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H

EPSS: 0.3% estimated probability of exploitation activity in the next 30 days; 19th percentile. Scored 2026-11-13. A forecast for this CVE across the internet, not for your own systems.
CISA's assessment (SSVC): Exploitation: none · Automatable: no · Technical impact: partial, assessed 2026-11-09. From CISA's Vulnrichment in the CVE List: whether it is exploited, whether exploiting it can be automated, and how much control it gives.
CWE: CWE-476 NULL Pointer Dereference
OWASP Top 10: A10:2025 Mishandling of Exceptional Conditions
Published: 2026-11-06 15:17 UTC
Modified: 2026-11-06 15:17 UTC
Assigned by: VulnCheck (CNA)
NVD analysis: Deferred: the NVD does not plan to analyze it
Record from: the NVD, synced 2026-11-06 15:42 UTC

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Affected

siyuan-note:siyuan

Versions

From the CNA's record in the CVE List.

Product	Affected
siyuan-note siyuan	before 3.8.9

References

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