CVE-2026-77217 PLANET Technology Corp. CVE debrief

Who should care

Defenders responsible for GS-4210-16P2S V3 devices should verify exposure and prioritize upgrading to version 3.441b260626 or later if vulnerable. This includes operators managing these devices, platform administrators, vulnerability management teams, and security teams that oversee the protection of these assets. They should review the supplied official advisory or CVE record to validate affected scope, severity, and vendor guidance, and plan vendor-

Why it matters

CVE-2026-77217 is a medium-severity vulnerability in PLANET GS-4210-16P2S V3 firmware before version 3.441b260626, allowing remote authenticated attackers to crash the CGI process or web management service via crafted requests.

• Denial of service via crafted requests to /cgi-bin/dispatcher.cgi
• Potential disruption of web management service
• Need to verify exposure of GS-4210-16P2S V3 devices
• Priority on upgrading to version 3.441b260626 or later

Technical summary

The vulnerability is caused by authenticated stack buffer overflow and null pointer dereference vulnerabilities in /cgi-bin/dispatcher.cgi. A remote authenticated attacker can send crafted requests to crash the CGI process or web management service, resulting in denial of service. The affected product, PLANET GS-4210-16P2S V3 firmware before version 3.441b260626, requires defensive measures to verify exposure and prioritize upgrading to the secure version. Defenders should focus on validating affected scope, severity, and vendor guidance.

Defensive priority

Defenders should prioritize verifying exposure of GS-4210-16P2S V3 devices and upgrading to version 3.441b260626 or later if vulnerable.

Recommended defensive actions

• Verify exposure of GS-4210-16P2S V3 devices
• Upgrade to version 3.441b260626 or later if vulnerable
• Monitor for crafted requests to /cgi-bin/dispatcher.cgi
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up

Evidence notes

The CVE record and NVD entry provide details on the vulnerability, including its description and CVSS score. However, the corpus does not establish versions, exploitation, impact, or remediation beyond upgrading to version 3.441b260626 or later.

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.