CVE-2026-23852

moderate-risk
Published 2026-01-19

SiYuan is a personal knowledge management system. Versions prior to 3.5.4 have a stored Cross-Site Scripting (XSS) vulnerability that allows an attacker to inject arbitrary HTML attributes into the `icon` attribute of a block via the `/api/attr/setBlockAttrs` API. The payload is later rendered in the dynamic icon feature in an unsanitized context, leading to stored XSS and, in the desktop environment, potential remote code execution (RCE). This issue bypasses the previous fix for issue `#15970` (XSS → RCE via dynamic icons). Version 3.5.4 contains an updated fix.

Do I need to act?

-
0.19% chance of exploitation
EPSS score — low exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.6/10 Critical
NETWORK / LOW complexity

Affected Products (1)

Affected Vendors

38
/ 100
moderate-risk
Severity 32/34 · Critical
Exploitability 1/34 · Minimal
Exposure 5/34 · Minimal