CVE-2022-4856: A vulnerability has been found in Modbus Tools Modbus Slave up to 7.5.1 and classified as critical

Q: How do I fix CVE-2022-4856?

modbus slave: upgrade to newer than 7.5.1. Exact commands for each OS are on this page.

Q: Is CVE-2022-4856 being exploited?

CVE-2022-4856 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2022-4856 affect?

CVE-2022-4856 affects modbus slave. Severity is medium (CVSS 6.3). A vulnerability has been found in Modbus Tools Modbus Slave up to 7.5.1 and classified as critical. Affected by this vulnerability is an unknown functionality of the file mbslave.exe of the component mbs File Handler. The manipulation leads

Q: How urgent is CVE-2022-4856?

Priority 39/100. Public exploit reference

Routine

MEDIUM 6.3UPGRADE

CVE-2022-4856 is a medium-severity flaw (CVSS 6.3) affecting modbus slave. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

A vulnerability has been found in Modbus Tools Modbus Slave up to 7.5.1 and classified as critical. Affected by this vulnerability is an unknown functionality of the file mbslave.exe of the component mbs File Handler. The manipulation leads to buffer overflow. The attack can be launched remotely. The exploit has been disclosed to the public and may be used. The identifier VDB-217021 was assigned to this vulnerability.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	6.3 (Medium)
Attack vector	Network (remote)
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.6% (top 51%)
CISA exploited list	No
Weakness	CWE-120
Published	2022-12-30
Last modified	2026-06-17

Publisher (CNA): VulDB · Vendor: modbustools

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

Am I affected?

Timeline

2022-12-30 10:15 UTCPublished CVE record published
2026-06-17 05:22 UTCUpdated Record last modified

modbustools modbus slave UPGRADE

Affected: <= 7.5.1

Fixed in: newer than 7.5.1

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy modbus-slave || rpm -q modbus-slave || modbus-slave --version

2. UPGRADE to newer than 7.5.1 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade modbus-slave

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade modbus-slave

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

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-2022-4856?

modbus slave: upgrade to newer than 7.5.1. Exact commands for each OS are on this page.

Is CVE-2022-4856 being exploited?

CVE-2022-4856 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-2022-4856 affect?

CVE-2022-4856 affects modbus slave. Severity is medium (CVSS 6.3). A vulnerability has been found in Modbus Tools Modbus Slave up to 7.5.1 and classified as critical. Affected by this vulnerability is an unknown functionality of the file mbslave.exe of the component mbs File Handler. The manipulation leads

How urgent is CVE-2022-4856?

Priority 39/100. Public exploit reference

Related CVEs

CVE-2022-1068 MEDIUM 5.5 UPGRADE Modbus Tools Modbus Slave (versions 7.4.2 and prior) is vulnerable to a stack-based buffer overflow in the reg

References

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