CVE-2026-74902 — HIGH (8.6)

Vulnerability Description

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.

CVSS Score

8.6

HIGH

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Attack Vector

LOCAL

Attack Complexity

LOW

Privileges Required

NONE

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality

HIGH

Integrity

HIGH

Availability

HIGH

Related Weaknesses (CWE)

CWE-79

References

FAQ

What is CVE-2026-74902?

CVE-2026-74902 is a vulnerability with a CVSS score of 8.6 (HIGH). 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 c...

How severe is CVE-2026-74902?

CVE-2026-74902 has been rated HIGH with a CVSS base score of 8.6/10. Review the CVSS metrics above for detailed severity breakdown.

Is there a patch for CVE-2026-74902?

Check the references section above for vendor advisories and patch information. Review vendor security bulletins for remediation guidance.