CVE-2026-56299 Capgo - Denial of Service via Unauthenticated OPTIONS Request to /build/upload Endpoint
Unauthenticated attackers can bypass authentication on the upload endpoint to trigger errors and cause denial of service via request flooding.
- 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-2026-56299?
CVE-2026-56299 is a medium-severity authentication bypass vulnerability in Capgo, published on 21 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 an authentication bypass vulnerability in the /build/upload/:jobId/* endpoint that allows unauthenticated attackers to trigger consistent 500 errors. Remote attackers can send OPTIONS requests to bypass authentication middleware and invoke tusProxy logic with invalid credentials, enabling trivial request flooding and denial of service.
Weakness: CWE-306
Which versions are affected by CVE-2026-56299?
How do I fix CVE-2026-56299?
No fix has been published for CVE-2026-56299 yet. Limit exposure of the affected software until one is available.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2026-56299 being exploited?
There is no known exploitation of CVE-2026-56299 in the wild and no public exploit code.
Sources
Also known as GHSA-33r3-cpxm-4xg2, GHSA-6c7m-4223-446j.