CVE-2026-56338 Capgo - Denial of Service in 2FA Email Verification via /auth/v1/otp Endpoint
Authenticated users are blocked from completing 2FA enrollment due to captcha validation failures causing HTTP 500 errors in the Capgo authentication endpoint.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- None listed
What is CVE-2026-56338?
CVE-2026-56338 is a medium-severity denial of service vulnerability in Capgo, published on 24 Jun 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
Capgo before 12.128.2 contains a denial of service vulnerability in the /auth/v1/otp endpoint that prevents email verification for two-factor authentication due to captcha validation failures. Authenticated users cannot complete 2FA enrollment as the backend consistently returns HTTP 500 errors with captcha verification process failed messages, blocking access to security controls.
Weakness: CWE-703
Which versions are affected by CVE-2026-56338?
How do I fix CVE-2026-56338?
No fix has been published for CVE-2026-56338 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-2026-56338 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-56338 exists.
Sources
Also known as GHSA-m53g-7gcj-x6f7.