CVE-2026-30618
Critical RCE in xszyou Fay 4.3.1 MCP STDIO management interface.
Is CVE-2026-30618 being exploited?
Not confirmed. CVE-2026-30618 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 1.2% probability of exploitation in the next 30 days.
How severe is CVE-2026-30618?
CVE-2026-30618 is rated Critical with a CVSS score of 9.8. 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-2026-30618?
Not known from our data. No patch reference has been recorded for CVE-2026-30618, which is not the same as no patch existing — a fix may have shipped without a tagged reference, or after this record was written. The vendor advisory is the only authority on whether a fix exists, and mitigations may be available regardless.
What does CVE-2026-30618 affect?
CVE-2026-30618 affects xszyou Fay 4.3.1, Fay MCP STDIO management interface. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-30618?
Isolate/disable MCP interface, block external access, apply vendor patch when released.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can configure MCP STDIO with malicious commands to achieve arbitrary command execution as the Fay service user.
Immediate action required