CVE-2021-26621: An Buffer Overflow vulnerability leading to remote code execution was discovered in MEX01

Q: How do I fix CVE-2021-26621?

mex01 firmware: upgrade to 1.9.18. Exact commands for each OS are on this page.

Q: Is CVE-2021-26621 being exploited?

CVE-2021-26621 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-2021-26621 affect?

CVE-2021-26621 affects mex01 firmware. Severity is high (CVSS 8.1). An Buffer Overflow vulnerability leading to remote code execution was discovered in MEX01. Remote attackers can use this vulnerability by using the property that the target program copies parameter values to memory through the strcpy() func

Q: How urgent is CVE-2021-26621?

Priority 53/100. High severity; Remotely exploitable, no login, no user action

This month

HIGH 8.1REMOTEUPGRADE

CVE-2021-26621 is a high-severity flaw (CVSS 8.1) affecting mex01 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An Buffer Overflow vulnerability leading to remote code execution was discovered in MEX01. Remote attackers can use this vulnerability by using the property that the target program copies parameter values to memory through the strcpy() function.

Why this priority

High severity
Remotely exploitable, no login, no user action

A fixed release or distro patch exists.

Risk facts

CVSS score	8.1 (High)
Attack vector	Network (remote)
Attack complexity	High
Privileges needed	None
User interaction	None
EPSS exploit chance	1.7% (top 22%)
CISA exploited list	No
Weakness	CWE-120
Published	2022-03-25
Last modified	2026-06-17

Publisher (CNA): KrCERT/CC · Vendor: netu

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

Am I affected?

Timeline

2022-03-25 19:15 UTCPublished CVE record published
2026-06-17 03:43 UTCUpdated Record last modified

netu mex01 firmware UPGRADE

Affected: < 1.9.18

Fixed in: 1.9.18

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-2021-26621?

mex01 firmware: upgrade to 1.9.18. Exact commands for each OS are on this page.

Is CVE-2021-26621 being exploited?

CVE-2021-26621 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-2021-26621 affect?

CVE-2021-26621 affects mex01 firmware. Severity is high (CVSS 8.1). An Buffer Overflow vulnerability leading to remote code execution was discovered in MEX01. Remote attackers can use this vulnerability by using the property that the target program copies parameter values to memory through the strcpy() func

How urgent is CVE-2021-26621?

Priority 53/100. High severity; Remotely exploitable, no login, no user action

References

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