CVE-2026-75126: Stack-based Buffer Overflow in PLANET Technology Corp. PLANET GS-4210-16P2S V3
Description
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.
CVSS v4.0
Score 6.9medium
Affected software
PLANET Technology Corp.
PLANET GS-4210-16P2S V3
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
Multiple authenticated stack buffer overflow vulnerabilities exist in PLANET GS-4210-16P2S V3 firmware prior to version 3.441b260626. The vulnerabilities are located in the /cgi-bin/dispatcher.cgi endpoint, where numerous handlers improperly copy POST parameters into fixed-size stack buffers without validating their length. This includes handlers related to VLAN membership, POE, SNTP, upgrade management, port counters, RMON statistics, cable diagnostics, AAA authentication lists, ACL management, SNMPv3 configuration, STP global settings, ISG database, TACACS, DHCP options, and others. Exploitation requires authentication and can cause the CGI process or web management service to crash, resulting in denial of service.
Potential Impact
An authenticated remote attacker can exploit these buffer overflow vulnerabilities to crash the CGI process or the web management service on the affected device. This results in denial of service, potentially disrupting network management and device availability. There is no indication of code execution or privilege escalation from the provided data.
Mitigation Recommendations
Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Until a fix is available, restrict access to the device's management interface to trusted administrators only and monitor for unusual crashes or service interruptions. Avoid sending crafted POST requests to the vulnerable handlers.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- VulnCheck
- Date Reserved
- 2026-08-17T18:39:57.660Z
- Cvss Version
- 4.0
- State
- PUBLISHED
Threat ID: 6a91e410acd9273b4942e881
Added to database: 08/28/2026, 19:40:00 UTC
Last enriched: 09/07/2026, 14:18:18 UTC
Last updated: 10/13/2026, 06:48:19 UTC
Views: 74
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