---
id: CVE-2026-75126
title: >-
  PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains multiple
  authenticated stack buffer overflow vulnerabilities in /cgi-bin/dispatcher.cgi
summary: >-
  PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains multiple
  authenticated stack buffer overflow vulnerabilities in
  /cgi-bin/dispatcher.cgi. The following handlers copy attacker-controlled POST
  parameters into fixed-size stack …
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
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-2026-75126'
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-via-dispatcher-cgi-standard-handlers
    label: disclosure@vulncheck.com
tags:
  - nvd
epss: 0.00602
epssPercentile: 0.46546
ingestedAt: '2026-09-08T21:11:12.287Z'
---

## Overview

PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains multiple authenticated stack buffer overflow vulnerabilities in /cgi-bin/dispatcher.cgi. The following handlers copy attacker-controlled POST parameters into fixed-size stack buffers without length validation: web_vlan_membership_edit_dialog_post; web_dai_vlan_post; web_poe_alive_rmtip_post; web_sys_sntp_post; web_tool_upgradeManager_post; web_port_countersClr_post; web_rmon_statisticsClr_post; web_cablediag_copper_post; web_aaa_*Authlist* handlers; web_acl_mgmt_Rules_Apply_post; web_acl_mgmt_Rules_Edit_post; web_acl_*AceDel_post handlers; web_acl_*AceAdd/Edit_post handlers; web_acl_bindAdd_post; web_acl_bindEdit_post; web_snmp_v3view_add_post; web_snmp_v3group_add_post; web_snmp_v3community_add_post; web_snmp_v3host_add_post; web_snmp_notifyv3_add_post; web_snmp_v3user_add_post; web_snmpv3_remote_engineId_add_post; web_stp_globalSetting_post; web_isg_db_post; web_tacplus*_post handlers; web_dhcp_option82_post; and web_dhcp_port_option82_cid_post. 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.