CVE-2026-1874
DoS in MELSEC FX5 Ethernet modules via UDP flood causing device reset.
Is CVE-2026-1874 being exploited?
Not confirmed. CVE-2026-1874 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 0.42% probability of exploitation in the next 30 days.
How severe is CVE-2026-1874?
CVE-2026-1874 is rated High with a CVSS score of 8.7. 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-2026-1874?
Yes. A fix has been recorded for CVE-2026-1874. The vendor advisory is the authority on the exact fixed version — apply it from there rather than from a summary.
What does CVE-2026-1874 affect?
CVE-2026-1874 affects Mitsubishi MELSEC iQ-F Series FX5-ENET/IP Ethernet Module FX5-ENET/IP v1.106 and earlier, Mitsubishi MELSEC iQ-F Series FX5-EIP EtherNet/IP Module (FX5-EIP) all versions. Confirm the exact affected versions against the vendor advisory before deciding you are exposed.
What should I do about CVE-2026-1874?
Apply firmware patch when released; restrict UDP access to affected devices.
Exploitation status reflects CISA's KEV catalog as we last synced it. Check the catalog directly.
Remote attacker can trigger DoS by UDP traffic; sustained floods cause a device reset, halting production.
Patch when possible
- affectedversions 1.000 and prior
- affectedversions 1.106 and prior
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.