CVE-2026-25223 (GCVE-0-2026-25223)

Vulnerability from cvelistv5 – Published: 2026-02-03 21:21 – Updated: 2026-02-04 21:18
VLAI?
Title
Fastify's Content-Type header tab character allows body validation bypass
Summary
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.
Severity ?
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
CWE
  • CWE-436 - Interpretation Conflict
Assigner
References
Impacted products
Vendor Product Version
fastify fastify Affected: < 5.7.2
Create a notification for this product.
Show details on NVD website
To clipboard 

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-25223",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-02-04T21:18:10.359742Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-02-04T21:18:16.693Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "fastify",
          "vendor": "fastify",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 5.7.2"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "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"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-436",
              "description": "CWE-436: Interpretation Conflict",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-02-03T21:21:40.268Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "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"
        }
      ],
      "source": {
        "advisory": "GHSA-jx2c-rxcm-jvmq",
        "discovery": "UNKNOWN"
      },
      "title": "Fastify\u0027s Content-Type header tab character allows body validation bypass"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-25223",
    "datePublished": "2026-02-03T21:21:40.268Z",
    "dateReserved": "2026-01-30T14:44:47.327Z",
    "dateUpdated": "2026-02-04T21:18:16.693Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": "{\"cve\":{\"id\":\"CVE-2026-25223\",\"sourceIdentifier\":\"security-advisories@github.com\",\"published\":\"2026-02-03T22:16:31.130\",\"lastModified\":\"2026-02-10T20:05:15.127\",\"vulnStatus\":\"Analyzed\",\"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.\"}],\"metrics\":{\"cvssMetricV31\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Secondary\",\"cvssData\":{\"version\":\"3.1\",\"vectorString\":\"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N\",\"baseScore\":7.5,\"baseSeverity\":\"HIGH\",\"attackVector\":\"NETWORK\",\"attackComplexity\":\"LOW\",\"privilegesRequired\":\"NONE\",\"userInteraction\":\"NONE\",\"scope\":\"UNCHANGED\",\"confidentialityImpact\":\"NONE\",\"integrityImpact\":\"HIGH\",\"availabilityImpact\":\"NONE\"},\"exploitabilityScore\":3.9,\"impactScore\":3.6}]},\"weaknesses\":[{\"source\":\"security-advisories@github.com\",\"type\":\"Primary\",\"description\":[{\"lang\":\"en\",\"value\":\"CWE-436\"}]}],\"configurations\":[{\"nodes\":[{\"operator\":\"OR\",\"negate\":false,\"cpeMatch\":[{\"vulnerable\":true,\"criteria\":\"cpe:2.3:a:fastify:fastify:*:*:*:*:*:node.js:*:*\",\"versionEndExcluding\":\"5.7.2\",\"matchCriteriaId\":\"51FAFCEB-4FBC-4777-BC6D-91713CA5828A\"}]}]}],\"references\":[{\"url\":\"https://fastify.dev/docs/latest/Reference/Validation-and-Serialization\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Product\",\"Technical Description\"]},{\"url\":\"https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/content-type-parser.js#L125\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Product\"]},{\"url\":\"https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Product\"]},{\"url\":\"https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Patch\"]},{\"url\":\"https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Vendor Advisory\",\"Mitigation\"]},{\"url\":\"https://hackerone.com/reports/3464114\",\"source\":\"security-advisories@github.com\",\"tags\":[\"Permissions Required\"]}]}}",
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-25223\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"none\"}, {\"Automatable\": \"no\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-02-04T21:18:10.359742Z\"}}}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-02-04T21:18:14.142Z\"}}], \"cna\": {\"title\": \"Fastify\u0027s Content-Type header tab character allows body validation bypass\", \"source\": {\"advisory\": \"GHSA-jx2c-rxcm-jvmq\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 7.5, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"HIGH\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N\", \"integrityImpact\": \"HIGH\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"NONE\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"fastify\", \"product\": \"fastify\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 5.7.2\"}]}], \"references\": [{\"url\": \"https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq\", \"name\": \"https://github.com/fastify/fastify/security/advisories/GHSA-jx2c-rxcm-jvmq\", \"tags\": [\"x_refsource_CONFIRM\"]}, {\"url\": \"https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821\", \"name\": \"https://github.com/fastify/fastify/commit/32d7b6add39ddf082d92579a58bea7018c5ac821\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://hackerone.com/reports/3464114\", \"name\": \"https://hackerone.com/reports/3464114\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://fastify.dev/docs/latest/Reference/Validation-and-Serialization\", \"name\": \"https://fastify.dev/docs/latest/Reference/Validation-and-Serialization\", \"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/content-type-parser.js#L125\", \"tags\": [\"x_refsource_MISC\"]}, {\"url\": \"https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272\", \"name\": \"https://github.com/fastify/fastify/blob/759e9787b5669abf953068e42a17bffba7521348/lib/validation.js#L272\", \"tags\": [\"x_refsource_MISC\"]}], \"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.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-436\", \"description\": \"CWE-436: Interpretation Conflict\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-02-03T21:21:40.268Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-25223\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-02-04T21:18:16.693Z\", \"dateReserved\": \"2026-01-30T14:44:47.327Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-02-03T21:21:40.268Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.




Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
  • Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
  • Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
  • Not confirmed: The user expressed doubt about the validity of the vulnerability.
  • Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.



Detection rules are retrieved from Rulezet.