{"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": "2026-09-21T14:22:34.126Z"}, "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"}}}}

{}

{"affected": [{"affectedData": [{"product": "nginx-ignition", "vendor": "lucasdillmann", "versions": [{"status": "affected", "version": ">= 2.29.0, < 2.40.1"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "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."}], "id": "CVE-2026-61629", "lastModified": "2026-09-21T15:17:30.477", "metrics": {"cvssMetricV31": [{"cvssData": {"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"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-09-21T15:17:30.477", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/lucasdillmann/nginx-ignition/commit/0c988fc1277c7d291725e8373313f8486fa1b31a"}, {"source": "security-advisories@github.com", "url": "https://github.com/lucasdillmann/nginx-ignition/commit/cbaf0fc16ed873f7178a2ca9b0d00a696e44b485"}, {"source": "security-advisories@github.com", "url": "https://github.com/lucasdillmann/nginx-ignition/security/advisories/GHSA-jr34-h97m-9hpx"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-770"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[2.29.0,2.40.1)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "cna", "scores": [{"score": 100.0, "source": "cna"}]}, "original": {"product": "nginx-ignition", "source": "cna", "vendor": "lucasdillmann"}, "product": "nginx-ignition", "vendor": "lucasdillmann"}], "created": "2026-09-21T15:45:16.126433+00:00", "updated": "2026-09-21T19:23:37.204542+00:00", "vendors": ["lucasdillmann", "lucasdillmann$PRODUCT$nginx-ignition"]}