CVE-2026-75126

Received Received - Intake

Authenticated Stack Buffer Overflow in PLANET GS-4210-16P2S Firmware

Publication date: 2026-08-28

Last updated on: 2026-08-28

Assigner: VulnCheck

Description

PLANET GS-4210-16P2S 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.

CVSS Scores

EPSS Scores

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Meta Information

Published

2026-08-28

Last Modified

2026-08-28

Generated

2026-08-29

AI Q&A

2026-08-29

EPSS Evaluated

N/A

NVD

CVE-2026-75126

EUVD

EUVD-2026-67786

Affected Vendors & Products

Vendor	Product	Version / Range
planet	gs-4210-16p2s	to 3.441b260626 (exc)

Helpful Resources

Exploitability

CWE

KEV

CWE ID	Description
CWE-121	A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function).

Attack-Flow Graph

Executive Summary

CVE-2026-75126 is a stack buffer overflow vulnerability in PLANET GS-4210-16P2S firmware before version 3.441b260626. It affects the /cgi-bin/dispatcher.cgi file where multiple authenticated handlers copy user-controlled POST parameters into fixed-size stack buffers without length checks. This includes handlers for VLAN, SNTP, firmware upgrades, ACL rules, SNMP, and DHCP settings.

Detection Guidance

To detect this vulnerability, check the firmware version of your PLANET GS-4210-16P2S device. If the version is before 3.441b260626, the device is vulnerable. Logs may show crashes in the CGI process or web management service after authenticated requests to affected handlers.

Impact Analysis

An authenticated remote attacker can exploit this flaw by sending specially crafted requests to crash the CGI process or web management service, causing a denial of service. This could disrupt network management and operations relying on the affected device.

Mitigation Strategies

Immediately update the firmware to version 3.441b260626 or later. Restrict access to the web management interface to trusted networks or IP addresses. Monitor for unusual activity or crashes in the CGI process.

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