PatchTheCVECVE-2026-74902: SiYuan before v3.7.4 contains a cross-site scripting vulnerability in the file upload validation flow that fai
CVE-2026-74902 is a high-severity flaw (CVSS 8.6) affecting affected software. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
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.
Why this priority
- High severity
A fixed release or distro patch exists.
Risk facts
| CVSS score | 8.6 (High) |
| Attack vector | Local |
| Attack complexity | Low |
| Privileges needed | None |
| User interaction | Required |
| EPSS exploit chance | 0.2% (top 91%) |
| CISA exploited list | No |
| Weakness | CWE-79 |
| Published | 2026-08-18 |
| Last modified | 2026-10-22 |
Last updated 2026-10-22 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Timeline
- Published CVE record published
- Updated Record last modified
Exact fixes by distribution
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-74902?
No fixed release is listed yet. Watch the vendor advisory and apply any mitigation shown on this page.
Is CVE-2026-74902 being exploited?
CVE-2026-74902 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-74902 affect?
CVE-2026-74902 affects affected software. Severity is high (CVSS 8.6). 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
How urgent is CVE-2026-74902?
Priority 32/100. High severity