{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-25223", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-01-30T14:44:47.327Z", "datePublished": "2026-02-03T21:21:40.268Z", "dateUpdated": "2026-02-03T21:21:40.268Z"}, "containers": {"cna": {"title": "Fastify's Content-Type header tab character allows body validation bypass", "problemTypes": [{"descriptions": [{"cweId": "CWE-436", "lang": "en", "description": "CWE-436: Interpretation Conflict", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}}], "references": [{"name": "https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq"}, {"name": "https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821", "tags": ["x_refsource_MISC"], "url": "https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821"}, {"name": "https://hackerone.com/reports/3464114", "tags": ["x_refsource_MISC"], "url": "https://hackerone.com/reports/3464114"}, {"name": "https://fastify.dev/docs/latest/Reference/Validation-and-Serialization", "tags": ["x_refsource_MISC"], "url": "https://fastify.dev/docs/latest/Reference/Validation-and-Serialization"}, {"name": "https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/content-type-parser.js#L125", "tags": ["x_refsource_MISC"], "url": "https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/content-type-parser.js#L125"}, {"name": "https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272", "tags": ["x_refsource_MISC"], "url": "https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272"}], "affected": [{"vendor": "fastify", "product": "fastify", "versions": [{"version": "< 5.7.2", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-02-03T21:21:40.268Z"}, "descriptions": [{"lang": "en", "value": "Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.2, a validation bypass vulnerability exists in Fastify where request body validation schemas specified by Content-Type can be completely circumvented. By appending a tab character (\\t) followed by arbitrary content to the Content-Type header, attackers can bypass body validation while the server still processes the body as the original content type. This issue has been patched in version 5.7.2."}], "source": {"advisory": "GHSA-jx2c-rxcm-jvmq", "discovery": "UNKNOWN"}}}}

{}

{"cveTags": [], "descriptions": [{"lang": "en", "value": "Fastify is a fast and low overhead web framework, for Node.js. Prior to version 5.7.2, a validation bypass vulnerability exists in Fastify where request body validation schemas specified by Content-Type can be completely circumvented. By appending a tab character (\\t) followed by arbitrary content to the Content-Type header, attackers can bypass body validation while the server still processes the body as the original content type. This issue has been patched in version 5.7.2."}], "id": "CVE-2026-25223", "lastModified": "2026-02-03T22:16:31.130", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "NONE", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-02-03T22:16:31.130", "references": [{"source": "security-advisories@github.com", "url": "https://fastify.dev/docs/latest/Reference/Validation-and-Serialization"}, {"source": "security-advisories@github.com", "url": "https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/content-type-parser.js#L125"}, {"source": "security-advisories@github.com", "url": "https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272"}, {"source": "security-advisories@github.com", "url": "https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821"}, {"source": "security-advisories@github.com", "url": "https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq"}, {"source": "security-advisories@github.com", "url": "https://hackerone.com/reports/3464114"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Received", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-436"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}