CVE-2021-47876 GeoGebra Classic 5.0.631.0-d - Denial of Service
Attackers can crash GeoGebra Classic by pasting oversized input into the Entrada field, causing a denial of service.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- None listed
What is CVE-2021-47876?
CVE-2021-47876 is a medium-severity denial of service vulnerability in GeoGebra Classic, published on 21 Jan 2026. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
GeoGebra Classic 5.0.631.0-d contains a denial of service vulnerability in the input field that allows attackers to crash the application by sending oversized buffer content. Attackers can generate a large buffer of 800,000 repeated characters and paste it into the 'Entrada:' input field to trigger an application crash.
Weakness: CWE-770
Which versions are affected by CVE-2021-47876?
How do I fix CVE-2021-47876?
No fix has been published for CVE-2021-47876 yet. Limit exposure of the affected software until one is available.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2021-47876 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2021-47876 exists.
Sources
Also known as GHSA-fqhq-3xgh-rx7h.