CVE-2026-74902

CVSS 9.3 (critical) · published 2026-08-18

SiYuan before v3.7.4 contains a cross-site scripting vulnerability in the file upload validation flow that fails to escape filenames before inserting them into HTML via insertAdjacentHTML. Attackers can craft a malicious filename containing script payloads that execute with full OS command access when a user drags, drops, or pastes the file into the editor.

Weakness: CWE-79

Source: NVD CVE-2026-74902

References

• https://github.com/siyuan-note/siyuan/security/advisories/GHSA-jf56-jrhq-j2qp
• https://www.vulncheck.com/advisories/siyuan-before-xss-to-rce-via-malicious-filename-upload

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