CVE-2023-4699: Missing Authentication for Critical Function vulnerability in Mitsubishi Electric Corporation MELSEC-F Series

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CRITICAL 10.0REMOTEMITIGATEMITIGATEMITIGATE

CVE-2023-4699 is a critical-severity flaw (CVSS 10.0) affecting fx3u-32mt\/es firmware, fx3u-48mt\/es firmware, fx3u-64mt\/es firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

Missing Authentication for Critical Function vulnerability in Mitsubishi Electric Corporation MELSEC-F Series CPU modules, MELSEC iQ-F Series, MELSEC iQ-R series CPU modules, MELSEC iQ-R series, MELSEC iQ-L series, MELSEC Q series, MELSEC-L series, Mitsubishi Electric CNC M800V/M80V series, Mitsubishi Electric CNC M800/M80/E80 series and Mitsubishi Electric CNC M700V/M70V/E70 series allows a remote unauthenticated attacker to execute arbitrary co

Why this priority

Critical severity
Remotely exploitable, no login, no user action

No fix is published yet: follow the downgrade or mitigation steps.

Risk facts

CVSS score	10.0 (Critical)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	None
EPSS exploit chance	0.8% (top 45%)
CISA exploited list	No
Weakness	CWE-306, CWE-345
Published	2023-11-06
Last modified	2026-06-17

Publisher (CNA): Mitsubishi Electric Corporation · Vendor: mitsubishielectric

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2023-11-06 06:15 UTCPublished CVE record published
2026-06-17 06:38 UTCUpdated Record last modified

mitsubishielectric fx3u-32mt\/es firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

mitsubishielectric fx3u-48mt\/es firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

mitsubishielectric fx3u-64mt\/es firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

mitsubishielectric fx3u-80mt\/es firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

mitsubishielectric fx3u-128mt\/e firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

mitsubishielectric fx3u-16mt\/es firmware MITIGATE

Affected: all versions

Fixed in: no fixed release known

Safe to downgrade to: no unaffected older release

Check your OS release

cat /etc/os-release; uname -r

Debian / Ubuntu

sudo apt update && sudo apt full-upgrade

RHEL / Amazon Linux / Fedora

sudo dnf upgrade --refresh

Windows

Install the latest cumulative update from Windows Update

If no patch exists yet

OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2023-4699?

fx3u-32mt\/es firmware: mitigate or apply the listed mitigation; fx3u-48mt\/es firmware: mitigate or apply the listed mitigation; fx3u-64mt\/es firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.

Is CVE-2023-4699 being exploited?

CVE-2023-4699 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2023-4699 affect?

CVE-2023-4699 affects fx3u-32mt\/es firmware, fx3u-48mt\/es firmware, fx3u-64mt\/es firmware. Severity is critical (CVSS 10.0). Missing Authentication for Critical Function vulnerability in Mitsubishi Electric Corporation MELSEC-F Series CPU modules, MELSEC iQ-F Series, MELSEC iQ-R series CPU modules, MELSEC iQ-R series, MELSEC iQ-L series, MELSEC Q series, MELSEC-L

How urgent is CVE-2023-4699?

Priority 54/100. Critical severity; Remotely exploitable, no login, no user action

Software pages

Mitsubishi Electric vulnerabilities

References

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