CVE-2026-74902
XSS in SiYuan file upload allows script and OS-command execution via crafted filenames.
Is CVE-2026-74902 being exploited?
Not confirmed. CVE-2026-74902 does not appear in CISA's Known Exploited Vulnerabilities catalog, which records only exploitation that has been observed and reported publicly. That is evidence of absence of a report, not evidence the flaw is unattacked. EPSS currently estimates a 0.15% probability of exploitation in the next 30 days.
How severe is CVE-2026-74902?
CVE-2026-74902 is rated Critical with a CVSS score of 9.3. Severity describes how bad exploitation would be, not how likely it is: pair it with exploitation evidence before deciding what to patch first.
Is there a patch for CVE-2026-74902?
Yes. A fix has been recorded for CVE-2026-74902. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74902 affect?
CVE-2026-74902 affects SiYuan < v3.7.4, SiYuan Editor (desktop/web). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74902?
Update SiYuan to v3.7.4 or later and avoid opening untrusted files.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Malicious filename XSS executes JavaScript in app context when user inserts a file, enabling OS command execution, potential RCE and data theft.
Immediate action required
- affected< 3.7.4
As published in the CVE Program record. A version outside these ranges is not a statement that it is unaffected — vendors sometimes understate a range, and distribution-backported builds carry upstream numbers that do not reflect what was patched into them.