CVE-2026-74800
Stored XSS via uploaded HTML assets in SiYuan allows script execution.
Is CVE-2026-74800 being exploited?
Not confirmed. CVE-2026-74800 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 0.29% probability of exploitation in the next 30 days.
How severe is CVE-2026-74800?
CVE-2026-74800 is rated Critical with a CVSS score of 9.4. 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-2026-74800?
Yes. A fix has been recorded for CVE-2026-74800. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-74800 affect?
CVE-2026-74800 affects SiYuan < v3.7.4 (desktop/workspace asset handling). Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-74800?
Upgrade SiYuan to v3.7.4+; restrict asset uploads and audit workspace users.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Authenticated users can upload HTML assets that trigger stored XSS in an owner's session, abusing kernel API for file access, command execution, 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.