FKIE_CVE-2026-45372

Vulnerability from fkie_nvd - Published: 2026-05-29 20:16 - Updated: 2026-06-01 19:16
Severity
9.9 (Critical) - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L
Summary
cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib's server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \r\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0.
References
security-advisories@github.comhttps://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4mExploit, Mitigation, Vendor Advisory
134c704f-9b21-4f2e-91b3-4a467353bcc0https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-xjxg-64p4-vj4mExploit, Mitigation, Vendor Advisory
Impacted products
Vendor Product Version
yhirose cpp-httplib *
To clipboard 

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              "matchCriteriaId": "80135DFE-EACD-44FD-990F-0239F78D0518",
              "versionEndExcluding": "0.44.0",
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  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.44.0, when cpp-httplib\u0027s server parses an incoming request, it applies percent-decoding to every header value except Location and Referer. The validity check (is_field_value) is run before decoding, so encoded %0D%0A passes the check and is then expanded to a literal \\r\\n byte pair inside the stored header value. This vulnerability is fixed in 0.44.0."
    }
  ],
  "id": "CVE-2026-45372",
  "lastModified": "2026-06-01T19:16:51.283",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 9.9,
          "baseSeverity": "CRITICAL",
          "confidentialityImpact": "LOW",
          "integrityImpact": "HIGH",
          "privilegesRequired": "NONE",
          "scope": "CHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:L/I:H/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 5.3,
        "source": "security-advisories@github.com",
        "type": "Secondary"
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  "published": "2026-05-29T20:16:26.473",
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  "vulnStatus": "Modified",
  "weaknesses": [
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      "description": [
        {
          "lang": "en",
          "value": "CWE-93"
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        {
          "lang": "en",
          "value": "CWE-444"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}


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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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  • Seen: The vulnerability was mentioned, discussed, or observed by the user.
  • Confirmed: The vulnerability has been validated from an analyst's perspective.
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