SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-74801

Attackers can create a malicious workspace directory with command metacharacters in its path and trigger the Microsoft Defender exclusion flow to execute arbitrary commands with administrator privileges after UAC approval.

HIGH 8.6EPSS 0.21%

Does this matter?

High impact if exploited, but EPSS currently rates exploitation as unlikely (0.21%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.

Description

SiYuan before 3.7.4 fails to properly escape workspace directory paths when constructing command-line arguments for the elevated elevator.exe helper process. Attackers can create a malicious workspace directory with command metacharacters in its path and trigger the Microsoft Defender exclusion flow to execute arbitrary commands with administrator privileges after UAC approval.

CVSS 4.0
8.6 HIGHCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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 · 10th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-78
Source
disclosure@vulncheck.com
EPSS trend
0%3%5%26 October 2026: 0.21%26 October 202626 October 2026

EPSS 0.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.