CVE-2026-77218Network attack vector

Authenticated web-management crash via unchecked credential copies

Published Aug 28, 2026 · Updated Aug 28, 2026

Stack buffer overflows in PLANET GS-4210-16P2S firmware before 3.441b260626 allow remote authenticated users to crash web management. The web_login_first_post, web_sys_enablePasswd_post, and web_sys_localUser_post handlers in /cgi-bin/dispatcher.cgi copy credential POST fields into fixed-size stack buffers without length validation. Administrator-level access to the affected credential workflows is required, and exploitation interrupts the CGI process or web-management service.

CVSS severity6.9
Medium
EPSS probability0.41%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Stack buffer overflows in PLANET GS-4210-16P2S firmware before 3.441b260626 allow remote authenticated users to crash web management. The web_login_first_post, web_sys_enablePasswd_post, and web_sys_localUser_post handlers in /cgi-bin/dispatcher.cgi copy credential POST fields into fixed-size stack buffers without length validation. Administrator-level access to the affected credential workflows is required, and exploitation interrupts the CGI process or web-management service.

The record

CVE
CVE-2026-77218
Published
Aug 28, 2026
Updated
Aug 28, 2026
Vendor
PLANET Technology Corporation
Product
PLANET GS-4210-16P2S
Classifications
CWE-121, T1499.004
Attack vector
network
Privileges
admin

Timeline

How it unfolded

  1. Aug 28, 2026CVE publishedPublication date reported by the CVE source.
  2. Aug 28, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=0 <3.441b260626

What conditions does exploitation require?

Attack vectornetwork
Required privilegesadmin

What is affected?

PLANET Technology Corporation · PLANET GS-4210-16P2Sversion=0 <3.441b260626

Published CVSS scores

4.9PLANET Technology CorporationCVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H
6.9PLANET Technology CorporationCVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

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No observations available

Sep 9, 2026Sep 15, 2026
Latest reporting daySep 15, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesadmin
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-121Stack-based Buffer Overflow
T1499.004Endpoint Denial of Service: Application or System Exploitation

Public exploit references

No public exploit references are available in this record.

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Technologies

Your stack

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Your stack

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