{"id":"CVE-2026-42882","revision":"214a08afffc34983be100731dd263bc2","records":[{"revision":"214a08afffc34983be100731dd263bc2","observedAt":"2026-10-27T11:12:04.713+00:00","statement":{"source":"nvd","id":"CVE-2026-42882","aliases":[],"title":"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 authentication…","description":"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 authentication middleware evaluates resource path patterns against the percent-encoded request URI (r.URL.RequestURI()), while the bucket handler constructs S3 object keys from the decoded path (r.URL.Path). This mismatch, combined with the glob library being invoked without a path separator (causing * to match across / boundaries), allows unauthenticated attackers to write to, read from, or delete objects in protected S3 namespaces. Exploitation is possible via three techniques: (1) using * patterns\nthat match across path separators to reach protected routes via path traversal (e.g., /open/foo/drafts/../restricted/), (2) using percent-encoded slashes (%2F) to collapse multiple path segments into a single token at the auth layer while the decoded form resolves to a protected namespace at the storage layer, and (3) using dot-dot segments (../) under ** prefix patterns, where the raw path matches an open route while Go's URL parser resolves the traversal to a protected path before the bucket handler runs. An unauthenticated attacker with network access can perform unauthorized PUT, GET, or DELETE operations on objects in authentication-protected S3 namespaces. This vulnerability is fixed in 5.0.0.","state":0,"publishedAt":"2026-05-11T20:25:44.45+00:00","modifiedAt":"2026-10-26T18:10:00.173+00:00","affected":[],"metrics":[{"system":"CVSS 3.1 · security-advisories@github.com · Secondary","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L","score":9.4,"severity":"CRITICAL"}],"references":["https://github.com/oxyno-zeta/s3-proxy/commit/1320e4abd46ad18c2851fedde50dbb79df8b7a51","https://github.com/oxyno-zeta/s3-proxy/commit/af5ff57d8c6022459495b8fb50130073bca7b48a","https://github.com/oxyno-zeta/s3-proxy/security/advisories/GHSA-rfgq-wgg8-662p"],"sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-42882","license":"NIST NVD usage terms; underlying source attribution retained","enrichment":{"sourceStatus":"Deferred","weaknesses":["CWE-22","CWE-863"],"productCriteria":[],"sourceDates":{"published":"2026-05-11T20:25:44.450","lastModified":"2026-10-26T18:10:00.173"},"relatedAdvisories":[],"note":"NVD analysis and CPE criteria are source context, not proof that a package or your environment is affected. Complete affected data, logical configurations and SSVC are retained in the original JSON."},"key":"nvd:CVE-2026-42882","identifiers":["CVE-2026-42882"]},"retained":false,"historicalAffected":[]}],"coverage":[]}