Vulnerability in Cap-Go Capgo
CVE-2026-56316
Cap-go before 12.128.2 contains an information disclosure vulnerability in the OPTIONS /build/upload/:jobId/* endpoint that allows unauthenticated attackers to enumerate valid builder job IDs through observable response discrepancies. Attackers can probe the endpoint without authentication to distinguish valid job IDs from invalid ones and generate sustained unauthenticated traffic for resource consumption.
Published · last modified .
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:L/I:N/A:N.
EPSS exploit prediction
EPSS: 0.004 (34.9th percentile), scored .
Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 35th percentile — 34.9% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.004 · newest: 0.004 · change: 0.000
Affected products
- Cap-Go Capgo — versions 0, 12.128.2
Weakness classification (CWE)
References
- github.com/Cap-go/capgo/security/advisories/GHSA-9c2x-7h5x-37gm (vendor-advisory)
- www.vulncheck.com/advisories/cap-go-job-existence-oracle-via-unauthenticated-op… (third-party-advisory)
Frequently asked questions
- What is CVE-2026-56316?
- CVE-2026-56316 is a medium-severity vulnerability in Cap-Go Capgo, classified under Observable Discrepancy. CVSS score: 5.3/10. Published 2026-06-21.
- How severe is CVE-2026-56316?
- Medium severity. CVSS v3 base score is 5.3 out of 10.