---
id: CVE-2026-77217
title: >-
  PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains authenticated
  stack buffer overflow and null pointer dereference vulnerabilities in
  /cgi-bin/dispatcher.cgi
summary: >-
  PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains authenticated
  stack buffer overflow and null pointer dereference vulnerabilities in
  /cgi-bin/dispatcher.cgi. The web_radiusSrv*_post family of handlers copies the
  radKey, radK…
severity: medium
cvss: 4.9
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H'
cwe:
  - CWE-121
  - CWE-476
published: '2026-08-28'
updated: '2026-09-08'
sourceUpdated: '2026-09-08T20:20:22.260'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-77217'
references:
  - url: 'https://www.planet.com.tw/en/support/security-advisory/10'
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/planet-gs-4210-16p2s-stack-buffer-overflow-and-null-pointer-dereference-via-dispatcher-cgi-radius-handlers
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00602
epssPercentile: 0.46472
ingestedAt: '2026-09-08T21:11:12.287Z'
---

## Overview

PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains authenticated stack buffer overflow and null pointer dereference vulnerabilities in /cgi-bin/dispatcher.cgi. The web_radiusSrv*_post family of handlers copies the radKey, radKey_0, radDftParamKey, radName, and radIp POST parameters into fixed-size stack buffers without length validation, and additionally dereferences radName and radIp without verifying their presence in the request. A remote authenticated attacker can send crafted requests to crash the CGI process or web management service, resulting in denial of service.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.