CVE-2025-61635 Add rate limiting to ApiFancyCaptchaReload
Attackers can exhaust resources by repeatedly triggering the FancyCaptcha reload API without rate limiting, causing service disruption.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2025-61635?
CVE-2025-61635 is a denial of service vulnerability in Wikimedia Foundation ConfirmEdit, published on 2 Feb 2026. An attacker can exploit it over the internet without logging in, and only if a user opens a file or follows a link.
Official description
Vulnerability in Wikimedia Foundation ConfirmEdit. This vulnerability is associated with program files includes/FancyCaptcha/ApiFancyCaptchaReload.Php.
This issue affects ConfirmEdit: *.
Which versions are affected by CVE-2025-61635?
How do I fix CVE-2025-61635?
Apply the vendor's patch.
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-2025-61635 being exploited?
There is no known exploitation of CVE-2025-61635 in the wild and no public exploit code.
Sources
Also known as DEBIAN-CVE-2025-61635, GHSA-gp65-637x-5v3w, UBUNTU-CVE-2025-61635.