SiYuan’s SVG sanitizer leaves animation tags such as <animate> and <set> unfiltered, allowing these elements to inject JavaScript when the SVG is rendered. The flaw is exploitable through an authentication‑free endpoint that returns dynamic icons, so an attacker can supply crafted SVG content and cause arbitrary script execution in a victim’s browser. This type of reflected XSS jeopardizes the confidentiality and integrity of data accessed by the victim while using the application.

The vulnerability affects the SiYuan personal knowledge‑management application provided by siyuan‑note, with the product name siyuan. Any installation running a version earlier than 3.5.10 is impacted; versions 3.5.9 and older contain the flaw, while 3.5.10 and later include the fix.

The severity rating of 6.4 indicates moderate risk, and the likelihood of a real‑world attack is low, with an exploit probability score below 1% and no listing in the CISA KEV catalog. Because the vulnerable interface does not require authentication, an attacker merely needs to construct a malicious SVG and submit it to the dynamic icon endpoint to trigger the script execution, making the exploitation straightforward once the bypass condition is recognized.