CVE-2026-75121
HIGHCVE-2026-75121 is a high-severity (CVSS 7.2) OS Command Injection vulnerability. O3 Security confirms whether CVE-2026-75121 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
PLANET GS-4210-16P2S firmware before 3.441b260626 contains an authenticated OS command injection vulnerability in /cgi-bin/dispatcher.cgi. The web_vlan_membership_edit_dialog_post handler…
Description
PLANET GS-4210-16P2S firmware before 3.441b260626 contains an authenticated OS command injection vulnerability in /cgi-bin/dispatcher.cgi. The web_vlan_membership_edit_dialog_post handler incorporates the memberTags POST parameter into a shell command without sanitization. A remote authenticated attacker can send a crafted memberTags value to execute arbitrary operating-system commands on the device.
Detection & mitigation playbook
VulnerabilityDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for the affected component. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Remediation status
No patched version of the affected component has shipped for CVE-2026-75121 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether CVE-2026-75121 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2026-75121. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2026-75121 in your dependencies?
O3 detects CVE-2026-75121 across dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.