{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-42882",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-04-30T18:49:06.711Z",
        "datePublished": "2026-05-11T19:26:44.897Z",
        "dateUpdated": "2026-05-13T14:40:36.658Z"
    },
    "containers": {
        "cna": {
            "title": "oxyno-zeta/s3-proxy: Security Issues in Resource Path Matching",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-22",
                            "lang": "en",
                            "description": "CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-863",
                            "lang": "en",
                            "description": "CWE-863: Incorrect Authorization",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "LOW",
                        "baseScore": 9.4,
                        "baseSeverity": "CRITICAL",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "HIGH",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:L",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/oxyno-zeta/s3-proxy/security/advisories/GHSA-rfgq-wgg8-662p",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/oxyno-zeta/s3-proxy/security/advisories/GHSA-rfgq-wgg8-662p"
                },
                {
                    "name": "https://github.com/oxyno-zeta/s3-proxy/commit/1320e4abd46ad18c2851fedde50dbb79df8b7a51",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/oxyno-zeta/s3-proxy/commit/1320e4abd46ad18c2851fedde50dbb79df8b7a51"
                },
                {
                    "name": "https://github.com/oxyno-zeta/s3-proxy/commit/af5ff57d8c6022459495b8fb50130073bca7b48a",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/oxyno-zeta/s3-proxy/commit/af5ff57d8c6022459495b8fb50130073bca7b48a"
                }
            ],
            "affected": [
                {
                    "vendor": "oxyno-zeta",
                    "product": "s3-proxy",
                    "versions": [
                        {
                            "version": "< 5.0.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-05-11T19:26:44.897Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "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."
                }
            ],
            "source": {
                "advisory": "GHSA-rfgq-wgg8-662p",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/oxyno-zeta/s3-proxy/security/advisories/GHSA-rfgq-wgg8-662p",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-05-13T13:11:55.482486Z",
                                "id": "CVE-2026-42882",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-05-13T14:40:36.658Z"
                }
            }
        ]
    }
}