Auth bypass in Capgo
CVE-2026-56299
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.
Vulnerability class: Broken Authentication
EPSS: 0.007 (51.0th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Capgo — versions 0, 12.128.2
Weakness classification (CWE)
References
- disclosure@vulncheck.com (vendor-advisory)
- disclosure@vulncheck.com (third-party-advisory)
Frequently asked questions
- What is CVE-2026-56299?
- CVE-2026-56299 is a medium-severity vulnerability in Capgo, classified under Missing Authentication for Critical Function. CVSS score: 5.3/10. Published 2026-06-21.
- How severe is CVE-2026-56299?
- Medium severity. CVSS v3 base score is 5.3 out of 10.