FKIE_CVE-2026-107721

Vulnerability from fkie_nvd - Published: 2026-10-08 22:17 - Updated: 2026-10-09 16:17
Severity
5.9 (Medium) - CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N
Summary
fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.0, fast-jwt createVerifier accepts Infinity for clockTolerance because its option validation checks type and negativity but not finiteness. In validateClaimDateValue, infinite positive and negative modifiers make exp and nbf comparisons always pass, allowing expired or not-yet-active tokens to be accepted. The verifier cache also derives infinite bounds, so entries created under this configuration can remain valid until eviction. Exploitation requires an application administrator or equivalent configuration path to set clockTolerance to Infinity. This issue is fixed in version 6.3.0.
References
security-advisories@github.comhttps://github.com/nearform/fast-jwt/commit/c0fb5b88b4c88ff2bdd194ca2c713599ad9e38b6
security-advisories@github.comhttps://github.com/nearform/fast-jwt/releases/tag/v6.3.0
security-advisories@github.comhttps://github.com/nearform/fast-jwt/security/advisories/GHSA-687g-22h4-j4w4
Impacted products
Vendor Product Version
To clipboard 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "fast-jwt",
          "vendor": "nearform",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 6.3.0"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to 6.3.0, fast-jwt createVerifier accepts Infinity for clockTolerance because its option validation checks type and negativity but not finiteness. In validateClaimDateValue, infinite positive and negative modifiers make exp and nbf comparisons always pass, allowing expired or not-yet-active tokens to be accepted. The verifier cache also derives infinite bounds, so entries created under this configuration can remain valid until eviction. Exploitation requires an application administrator or equivalent configuration path to set clockTolerance to Infinity. This issue is fixed in version 6.3.0."
    }
  ],
  "id": "CVE-2026-107721",
  "lastModified": "2026-10-09T16:17:23.590",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "HIGH",
          "attackVector": "NETWORK",
          "availabilityImpact": "NONE",
          "baseScore": 5.9,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "HIGH",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:N",
          "version": "3.1"
        },
        "exploitabilityScore": 0.7,
        "impactScore": 5.2,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-107721",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-09T15:00:04.372564Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-10-08T22:17:28.263",
  "references": [
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/nearform/fast-jwt/commit/c0fb5b88b4c88ff2bdd194ca2c713599ad9e38b6"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/nearform/fast-jwt/releases/tag/v6.3.0"
    },
    {
      "source": "security-advisories@github.com",
      "url": "https://github.com/nearform/fast-jwt/security/advisories/GHSA-687g-22h4-j4w4"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-613"
        },
        {
          "lang": "en",
          "value": "CWE-682"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}



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