SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-74903

SiYuan before v3.7.4 contains an insufficient access control vulnerability in the /api/lute/spinBlockDOM endpoint, which is guarded only by CheckAuth middleware instead of CheckAdminRole like its sibling endpoint.

MEDIUM 5.3EPSS 0.21%

Does this matter?

Lower severity and a low EPSS score (0.21%). Track it; it rarely justifies an emergency change on its own.

Description

SiYuan before v3.7.4 contains an insufficient access control vulnerability in the /api/lute/spinBlockDOM endpoint, which is guarded only by CheckAuth middleware instead of CheckAdminRole like its sibling endpoint. Authenticated users with RoleEditor or RoleReader roles can invoke the endpoint to transform arbitrary DOM input, and large payloads cause endpoint starvation through per-path mutex serialization.

CVSS 4.0
5.3 MEDIUMCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:L/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
0.21% probability · 11th percentile
CISA KEV
Not listed
Weakness
CWE-400
Source
disclosure@vulncheck.com

Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.