CVE-2026-77217 PLANET GS-4210-16P2S V3 Stack Buffer Overflow and NULL Pointer Dereference via dispatcher.cgi RADIUS Handlers
Authenticated attackers can cause denial of service on PLANET GS-4210-16P2S V3 switches via stack buffer overflow and null pointer dereference in dispatcher.cgi.
- Exploited in the wild
- Not known
- Login needed
- An administrator
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-77217?
CVE-2026-77217 is a medium-severity memory corruption vulnerability in PLANET GS-4210-16P2S V3, published on 28 Aug 2026. An attacker needs administrator access to exploit it, with no action from the victim.
Official description
PLANET GS-4210-16P2S V3 firmware before 3.441b260626 contains authenticated stack buffer overflow and null pointer dereference vulnerabilities in /cgi-bin/dispatcher.cgi. The web_radiusSrv*_post family of handlers copies the radKey, radKey_0, radDftParamKey, radName, and radIp POST parameters into fixed-size stack buffers without length validation, and additionally dereferences radName and radIp without verifying their presence in the request. A remote authenticated attacker can send crafted requests to crash the CGI process or web management service, resulting in denial of service.
Which versions are affected by CVE-2026-77217?
How do I fix CVE-2026-77217?
No fix has been published for CVE-2026-77217 yet. Limit exposure of the affected software until one is available.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2026-77217 being exploited?
There is no known exploitation of CVE-2026-77217 in the wild and no public exploit code.
Sources
Also known as GHSA-m873-gx73-4mvm.