{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-55430",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-06-16T21:59:57.017Z",
        "datePublished": "2026-07-08T00:03:29.728Z",
        "dateUpdated": "2026-07-08T17:10:40.949Z"
    },
    "containers": {
        "cna": {
            "title": "Coder's subdomain workspace app routing trusts unauthenticated X-Forwarded-Host header, enabling cross-app data access",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-345",
                            "lang": "en",
                            "description": "CWE-345: Insufficient Verification of Data Authenticity",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-441",
                            "lang": "en",
                            "description": "CWE-441: Unintended Proxy or Intermediary ('Confused Deputy')",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "HIGH",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 5.8,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "LOW",
                        "scope": "CHANGED",
                        "userInteraction": "REQUIRED",
                        "vectorString": "CVSS:3.1/AV:N/AC:H/PR:L/UI:R/S:C/C:H/I:N/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/coder/coder/security/advisories/GHSA-5g4w-3vw9-478w",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/coder/coder/security/advisories/GHSA-5g4w-3vw9-478w"
                },
                {
                    "name": "https://github.com/coder/coder/pull/26204",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/coder/coder/pull/26204"
                },
                {
                    "name": "https://github.com/coder/coder/releases/tag/v2.29.17",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/coder/coder/releases/tag/v2.29.17"
                },
                {
                    "name": "https://github.com/coder/coder/releases/tag/v2.32.7",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/coder/coder/releases/tag/v2.32.7"
                },
                {
                    "name": "https://github.com/coder/coder/releases/tag/v2.33.8",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/coder/coder/releases/tag/v2.33.8"
                },
                {
                    "name": "https://github.com/coder/coder/releases/tag/v2.34.2",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/coder/coder/releases/tag/v2.34.2"
                }
            ],
            "affected": [
                {
                    "vendor": "coder",
                    "product": "coder",
                    "versions": [
                        {
                            "version": ">= 2.34.0, < 2.34.2",
                            "status": "affected"
                        },
                        {
                            "version": ">= 2.33.0, < 2.33.8",
                            "status": "affected"
                        },
                        {
                            "version": ">= 2.30.0, < 2.32.7",
                            "status": "affected"
                        },
                        {
                            "version": "< 2.29.17",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-07-08T00:03:29.728Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Coder allows organizations to provision remote development environments via Terraform. Prior to versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2, the workspace app proxy resolves the target app from `httpapi.RequestHost()` which prefers the `X-Forwarded-Host` header over the real `Host` header. No middleware strips `X-Forwarded-Host` before routing and the header is not browser-forbidden so client-side JavaScript can set it on `fetch()` calls. Practical exploitation requires subdomain app routing (wildcard hostname) enabled, a victim who visits the attacker's shared app and a deployment whose upstream proxy does not strip `X-Forwarded-Host`. The fix in versions 2.29.7, 2.32.7, 2.33.8, and 2.34.2 trusts `X-Forwarded-Host` only from configured trusted proxies and otherwise resolves the routing host from the verified request host. As a workaround, place an upstream reverse proxy that strips or overwrites `X-Forwarded-Host` on untrusted requests."
                }
            ],
            "source": {
                "advisory": "GHSA-5g4w-3vw9-478w",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-07-08T16:57:10.249359Z",
                                "id": "CVE-2026-55430",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "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": "2026-07-08T17:10:40.949Z"
                }
            }
        ]
    }
}