that 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.
Analysis and contextual insights are available on OpenCVE Cloud.
No vendor fix or workaround currently provided.
Additional remediation guidance may be available on OpenCVE Cloud.
Tracking
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| Source | ID | Title |
|---|---|---|
Github GHSA |
GHSA-rfgq-wgg8-662p | S3-Proxy has Security Issues in its Resource Path Matching Implementation |
Wed, 13 May 2026 16:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Metrics |
ssvc
|
Mon, 11 May 2026 23:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| First Time appeared |
Oxyno-zeta
Oxyno-zeta s3-proxy |
|
| Vendors & Products |
Oxyno-zeta
Oxyno-zeta s3-proxy |
Mon, 11 May 2026 20:15:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| 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 that 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. | |
| Title | oxyno-zeta/s3-proxy: Security Issues in Resource Path Matching | |
| Weaknesses | CWE-22 CWE-863 |
|
| References |
| |
| Metrics |
cvssV3_1
|
Status: PUBLISHED
Assigner: GitHub_M
Published:
Updated: 2026-05-13T14:40:36.658Z
Reserved: 2026-04-30T18:49:06.711Z
Link: CVE-2026-42882
Updated: 2026-05-13T13:12:14.781Z
Status : Deferred
Published: 2026-05-11T20:25:44.450
Modified: 2026-05-13T18:31:17.630
Link: CVE-2026-42882
No data.
OpenCVE Enrichment
Updated: 2026-05-11T23:00:19Z
Github GHSA