What is CVE-2026-42882?

CVE-2026-42882 is a critical-severity vulnerability in Oxyno-zeta S3-proxy, classified under Path Traversal. CVSS score: 9.4/10. Published 2026-05-11.

How severe is CVE-2026-42882?

Critical severity. CVSS v3 base score is 9.4 out of 10.

Auth bypass in Oxyno-zeta S3-proxy

CVE-2026-42882

oxyno-zeta/s3-proxy is an aws s3 proxy written in go. Prior to 5.0.0, s3-proxy contains an authentication bypass caused by inconsistent URL path interpretation between the authentication middleware and the bucket handler. The authenticatio…

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.002 (41.4th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.4 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L.

Affected products

Oxyno-zeta S3-proxy — versions < 5.0.0

Weakness classification (CWE)

References

security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_MISC)
security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-42882?: CVE-2026-42882 is a critical-severity vulnerability in Oxyno-zeta S3-proxy, classified under Path Traversal. CVSS score: 9.4/10. Published 2026-05-11.
How severe is CVE-2026-42882?: Critical severity. CVSS v3 base score is 9.4 out of 10.