CVE-2026-34585
Prior to version 3.6.2, a vulnerability allows crafted block attribute values to bypass server-side attribute escaping when an HTML entity is mixed with raw special characters.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.34%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
SiYuan is a personal knowledge management system. Prior to version 3.6.2, a vulnerability allows crafted block attribute values to bypass server-side attribute escaping when an HTML entity is mixed with raw special characters. An attacker can embed a malicious IAL value inside a .sy document, package it as a .sy.zip, and have the victim import it through the normal Import -> SiYuan .sy.zip workflow. Once the note is opened, the malicious attribute breaks out of its original HTML context and injects an event handler, resulting in stored XSS. In the Electron desktop client, this XSS reaches remote code execution because injected JavaScript runs with access to Node/Electron APIs. This issue has been patched in version 3.6.2.
- CVSS 3.1
- 8.2 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:C/C:H/I:H/A:H
- EPSS
- 0.34% probability · 27th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79, CWE-94
- Affected
- b3log/siyuan
- Source
- security-advisories@github.com
References
- https://github.com/siyuan-note/siyuan/issues/17246Issue Tracking
- https://github.com/siyuan-note/siyuan/releases/tag/v3.6.2Release Notes
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-ff66-236v-p4fgExploit, Vendor Advisory
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-ff66-236v-p4fgExploit, Vendor Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.