{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-27977",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-02-25T03:24:57.793Z",
        "datePublished": "2026-03-17T23:56:24.631Z",
        "dateUpdated": "2026-03-18T19:56:16.843Z"
    },
    "containers": {
        "cna": {
            "title": "Next.js: null origin can bypass dev HMR websocket CSRF checks",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-1385",
                            "lang": "en",
                            "description": "CWE-1385: Missing Origin Validation in WebSockets",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "PRESENT",
                        "privilegesRequired": "NONE",
                        "userInteraction": "PASSIVE",
                        "vulnConfidentialityImpact": "LOW",
                        "vulnIntegrityImpact": "LOW",
                        "vulnAvailabilityImpact": "NONE",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 2.3,
                        "baseSeverity": "LOW",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:P/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/vercel/next.js/security/advisories/GHSA-jcc7-9wpm-mj36",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/vercel/next.js/security/advisories/GHSA-jcc7-9wpm-mj36"
                },
                {
                    "name": "https://github.com/vercel/next.js/commit/862f9b9bb41d235e0d8cf44aa811e7fd118cee2a",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/vercel/next.js/commit/862f9b9bb41d235e0d8cf44aa811e7fd118cee2a"
                },
                {
                    "name": "https://github.com/vercel/next.js/releases/tag/v16.1.7",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/vercel/next.js/releases/tag/v16.1.7"
                }
            ],
            "affected": [
                {
                    "vendor": "vercel",
                    "product": "next.js",
                    "versions": [
                        {
                            "version": ">= 16.0.1, < 16.1.7",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-03-18T00:23:47.523Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Next.js is a React framework for building full-stack web applications. Starting in version 16.0.1 and prior to version 16.1.7, in `next dev`, cross-site protection for internal websocket endpoints could treat `Origin: null` as a bypass case even if `allowedDevOrigins` is configured, allowing privacy-sensitive/opaque contexts (for example sandboxed documents) to connect unexpectedly. If a dev server is reachable from attacker-controlled content, an attacker may be able to connect to the HMR websocket channel and interact with dev websocket traffic. This affects development mode only. Apps without a configured `allowedDevOrigins` still allow connections from any origin. The issue is fixed in version 16.1.7 by validating `Origin: null` through the same cross-site origin-allowance checks used for other origins. If upgrading is not immediately possible, do not expose `next dev` to untrusted networks and/or block websocket upgrades to `/_next/webpack-hmr` when `Origin` is `null` at the proxy."
                }
            ],
            "source": {
                "advisory": "GHSA-jcc7-9wpm-mj36",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-03-18T19:56:08.547586Z",
                                "id": "CVE-2026-27977",
                                "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": "2026-03-18T19:56:16.843Z"
                }
            }
        ]
    }
}