8.8High
CVE-2026-92986
SiYuan before 3.8.4 renders document titles as HTML in the backlink dock tree without escaping markup characters. Attackers can set malicious titles through the rename API or crafted notebooks to execute scripts in the Electron renderer with access to child_process for command execution.
What this means for your business
- An attacker can use it remotely, over a network, without a login, but only after tricking someone into an action such as opening a file or a link.
What to do
- 1Ask your IT team or provider whether any of your systems use the affected product.
- 2If you do, follow the vendor's guidance. No patch reference has been published yet.
Not sure if your company is exposed?
Fastnexa’s certified penetration testers can check whether attackers could use this flaw, or others like it, against your websites, apps and network. The full test is free for our first 10 founding clients until 31 December 2026.
Scoring
- CVSS
- 8.8 (v3.1)
- Vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H- CVSS v4
- 8.6
- Weakness
- CWE-79
- Assigned by
- disclosure@vulncheck.com
Dates
- Published
- 2026-09-17
- Last modified
- 2026-09-17
- Sources
- NVD
References
- https://github.com/siyuan-note/siyuan
- https://github.com/siyuan-note/siyuan/blob/v3.8.3/app/src/util/Tree.ts#L134
- https://github.com/siyuan-note/siyuan/commit/6f093ebe50afc503e2a8b056164293054f8509e7
- https://github.com/siyuan-note/siyuan/security/advisories/GHSA-c5h9-g2c6-fxjw
- https://www.vulncheck.com/advisories/siyuan-before-3.8.4-cross-site-scripting-via-document-title