Is CVE-2026-77218 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-77218 being exploited in the wild.

How severe is CVE-2026-77218?

Medium severity, with a CVSS score of 4.9, published 28 August 2026.

Which products and versions are affected?

PLANET GS-4210-16P2S V3 before 3.441b260626.

Is there a fix for CVE-2026-77218?

No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

How is CVE-2026-77218 attacked?

It is attacked over the network, in device firmware.

Am I affected by CVE-2026-77218?

Check whether you run PLANET GS-4210-16P2S V3 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-77218: PLANET GS-4210-16P2S V3 stack buffer overflow in dispatcher.cgi

CVE-2026-77218 · Severity: medium · CVSS 4.9 · Published 2026-08-28

The PLANET GS-4210-16P2S V3 is a managed network switch with a built-in web management interface. The firmware contains authenticated stack buffer overflow vulnerabilities in credential-handling functions that allow an authenticated attacker to crash the web management service, resulting in a denial of service and preventing legitimate administrators from managing the device.

Technologies: PLANET GS-4210-16P2S V3. Vendors: PLANET.

Quick answers

Is CVE-2026-77218 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-77218 being exploited in the wild.
How severe is CVE-2026-77218?: Medium severity, with a CVSS score of 4.9, published 28 August 2026.
Which products and versions are affected?: PLANET GS-4210-16P2S V3 before 3.441b260626.
Is there a fix for CVE-2026-77218?: No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.
How is CVE-2026-77218 attacked?: It is attacked over the network, in device firmware.
Am I affected by CVE-2026-77218?: Check whether you run PLANET GS-4210-16P2S V3 at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

Stack-based buffer overflow vulnerabilities (CWE-121) exist in three authenticated handlers within /cgi-bin/dispatcher.cgi: web_login_first_post (usrPass parameter), web_sys_enablePasswd_post (enbPass parameter), and web_sys_localUser_post (usrName and usrPass parameters). Each handler copies POST parameters into fixed-size stack buffers without length validation, allowing oversized input to overflow. Attack requires prior authentication to the web management interface. Successful exploitation causes the CGI process or web management service to crash, resulting in denial of service. Patched firmware version 3.441b260626 and later address the vulnerability.

Affected products

PLANET GS-4210-16P2S V3 before 3.441b260626

Timeline

2026-08-28: disclosed

References

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