SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2026-87814

SiYuan before v3.8.2 contains a stored cross-site scripting vulnerability in the search asset preview feature that fails to escape indexed asset content before inserting it into the DOM using innerHTML.

HIGH 8.4EPSS 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 v3.8.2 contains a stored cross-site scripting vulnerability in the search asset preview feature that fails to escape indexed asset content before inserting it into the DOM using innerHTML. Attackers who can place crafted text assets in a workspace can execute JavaScript in the SiYuan origin when victims preview the assets, enabling authenticated API requests and workspace manipulation.

CVSS 4.0
8.4 HIGHCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/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-79
Source
disclosure@vulncheck.com

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