{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-61629",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-07-10T17:38:57.110Z",
        "datePublished": "2026-09-21T14:22:34.126Z",
        "dateUpdated": "2026-09-24T22:11:44.377Z"
    },
    "containers": {
        "cna": {
            "title": "nginx ignition has  ParseAcceptLanguage `_` separator bypass that enables ~75x CPU amplification via Accept-Language header in i18nMiddleware",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-770",
                            "lang": "en",
                            "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "HIGH",
                        "baseScore": 7.5,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "NONE",
                        "integrityImpact": "NONE",
                        "privilegesRequired": "NONE",
                        "scope": "UNCHANGED",
                        "userInteraction": "NONE",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-jr34-h97m-9hpx",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-jr34-h97m-9hpx"
                },
                {
                    "name": "https://github.com/lucasdillmann/nginx-ignition/commit/0c988fc1277c7d291725e8373313f8486fa1b31a",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/lucasdillmann/nginx-ignition/commit/0c988fc1277c7d291725e8373313f8486fa1b31a"
                },
                {
                    "name": "https://github.com/lucasdillmann/nginx-ignition/commit/cbaf0fc16ed873f7178a2ca9b0d00a696e44b485",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/lucasdillmann/nginx-ignition/commit/cbaf0fc16ed873f7178a2ca9b0d00a696e44b485"
                }
            ],
            "affected": [
                {
                    "vendor": "lucasdillmann",
                    "product": "nginx-ignition",
                    "versions": [
                        {
                            "version": ">= 2.29.0, < 2.40.1",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-09-21T14:22:34.126Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "nginx ignition is a user interface for the nginx web server. In versions 2.29.0 through 2.40.0, the gin i18n middleware in nginx-ignition's API server runs in front of every HTTP request and calls `golang.org/x/text/language.ParseAcceptLanguage` on the raw `Accept-Language` header without imposing any size or shape filter. The underlying parser has quadratic-time behaviour on long lists of malformed language tags. The CVE-2022-32149 guard that golang.org/x/text added in v0.3.8 caps the number of `-` characters in the input at 1000, but it does not cap `_` characters even though the parser's internal scanner aliases `_` to `-` before parsing. A single unauthenticated GET request with an `Accept-Language` header built out of `_` separators burns about 2.4 seconds of server CPU on the host running nginx-ignition; ten concurrent attackers saturate a ten-core box for the duration of the attack while consuming ~10 MiB/s of upstream bandwidth. Version 2.40.1 fixes this issue."
                }
            ],
            "source": {
                "advisory": "GHSA-jr34-h97m-9hpx",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-jr34-h97m-9hpx",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-24T22:11:10.143630Z",
                                "id": "CVE-2026-61629",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "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": "2026-09-24T22:11:44.377Z"
                }
            }
        ]
    }
}