{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-33490",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-03-20T16:16:48.971Z",
        "datePublished": "2026-03-26T17:19:15.956Z",
        "dateUpdated": "2026-03-26T18:23:39.653Z"
    },
    "containers": {
        "cna": {
            "title": "h3: Missing Path Segment Boundary Check in `mount()` Causes Middleware Execution on Unrelated Prefix-Matching Routes",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-706",
                            "lang": "en",
                            "description": "CWE-706: Use of Incorrectly-Resolved Name or Reference",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "HIGH",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 3.7,
                        "baseSeverity": "LOW",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "LOW",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:L/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/h3js/h3/security/advisories/GHSA-2j6q-whv2-gh6w",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/h3js/h3/security/advisories/GHSA-2j6q-whv2-gh6w"
                }
            ],
            "affected": [
                {
                    "vendor": "h3js",
                    "product": "h3",
                    "versions": [
                        {
                            "version": ">= 2.0.1-alpha.0, < 2.0.1-rc.17",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-03-26T17:19:15.956Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "H3 is a minimal H(TTP) framework. In versions 2.0.0-0 through 2.0.1-rc.16, the `mount()` method in h3 uses a simple `startsWith()` check to determine whether incoming requests fall under a mounted sub-application's path prefix. Because this check does not verify a path segment boundary (i.e., that the next character after the base is `/` or end-of-string), middleware registered on a mount like `/admin` will also execute for unrelated routes such as `/admin-public`, `/administrator`, or `/adminstuff`. This allows an attacker to trigger context-setting middleware on paths it was never intended to cover, potentially polluting request context with unintended privilege flags. Version 2.0.2-rc.17 contains a patch."
                }
            ],
            "source": {
                "advisory": "GHSA-2j6q-whv2-gh6w",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/h3js/h3/security/advisories/GHSA-2j6q-whv2-gh6w",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-03-26T17:46:14.997707Z",
                                "id": "CVE-2026-33490",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-03-26T18:23:39.653Z"
                }
            }
        ]
    }
}