FKIE_CVE-2026-45372

Vulnerability from fkie_nvd - Published: 2026-05-29 20:16 - Updated: 2026-07-22 06:10
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 

{
  "affected": [
    {
      "affectedData": [
        {
          "product": "cpp-httplib",
          "vendor": "yhirose",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.44.0"
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  "configurations": [
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              "versionEndExcluding": "0.44.0",
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  "cveTags": [],
  "descriptions": [
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      "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."
    },
    {
      "lang": "es",
      "value": "cpp-httplib es una biblioteca HTTP/HTTPS multiplataforma de un solo archivo de cabecera para C++11. Antes de la 0.44.0, cuando el servidor de cpp-httplib analiza una solicitud entrante, aplica la decodificaci\u00f3n de porcentaje a cada valor de cabecera, excepto a Location y Referer. La comprobaci\u00f3n de validez (is_field_value) se ejecuta antes de la decodificaci\u00f3n, por lo que el %0D%0A codificado pasa la comprobaci\u00f3n y luego se expande a un par de bytes literal \\r\\n dentro del valor de cabecera almacenado. Esta vulnerabilidad se corrige en la 0.44.0."
    }
  ],
  "id": "CVE-2026-45372",
  "lastModified": "2026-07-22T06:10:00.170",
  "metrics": {
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          "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"
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            {
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          "role": "CISA Coordinator",
          "timestamp": "2026-06-01T17:57:24.969798Z",
          "version": "2.0.3"
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  "published": "2026-05-29T20:16:26.473",
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  "vulnStatus": "Modified",
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      "source": "security-advisories@github.com",
      "type": "Secondary"
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}



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