Is CVE-2026-74800 being exploited?

No public exploit is currently tracked.

How severe is CVE-2026-74800?

CVE-2026-74800 has a CVSS v3 severity of CRITICAL (9).

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CVE-2026-74800

Description

SiYuan before v3.7.4 fails to set Content-Disposition and X-Content-Type-Options headers when serving arbitrary file assets, allowing stored cross-site scripting attacks. Authenticated attackers can upload HTML files as assets and execute scripts with full kernel API access when the workspace owner opens the asset link.