{
  "affected": [
    {
      "affectedData": [
        {
          "product": "cpp-httplib",
          "vendor": "yhirose",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.43.4"
            }
          ]
        }
      ],
      "source": "security-advisories@github.com"
    }
  ],
  "configurations": [
    {
      "nodes": [
        {
          "cpeMatch": [
            {
              "criteria": "cpe:2.3:a:yhirose:cpp-httplib:*:*:*:*:*:*:*:*",
              "matchCriteriaId": "E8AD5B92-E320-454E-B226-B5312048001D",
              "versionEndExcluding": "0.43.4",
              "vulnerable": true
            }
          ],
          "negate": false,
          "operator": "OR"
        }
      ]
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "cpp-httplib is a C++11 single-file header-only cross platform HTTP/HTTPS library. Prior to 0.43.4, negative chunk-size in chunked Transfer-Encoding causes unbounded memory allocation and process crash. The ChunkedDecoder::read_payload function in cpp-httplib (httplib.h) parses the chunk-size field of HTTP chunked transfer encoding using std::strtoul(). Per the C standard (\u00a77.22.1.4), strtoul silently accepts a leading minus sign, performing unsigned wrap-around: strtoul(\"-2\", \u2026, 16) returns ULONG_MAX \u2212 1 (0xFFFFFFFFFFFFFFFE). The library\u0027s only guard (line 12833) rejects ULONG_MAX (the result of \"-1\"), but any other negative value such as \"-2\" passes validation. The resulting near-maximum value is stored in chunk_remaining and controls how many bytes the server\u0027s read loop consumes from the network. This vulnerability is fixed in 0.43.4."
    },
    {
      "lang": "es",
      "value": "cpp-httplib es una biblioteca HTTP/HTTPS multiplataforma de C++11 de un solo archivo de solo encabezado. Antes de la 0.43.4, un tama\u00f1o de fragmento negativo en la codificaci\u00f3n de transferencia fragmentada (chunked Transfer-Encoding) causa una asignaci\u00f3n de memoria ilimitada y la ca\u00edda del proceso. La funci\u00f3n ChunkedDecoder::read_payload en cpp-httplib (httplib.h) analiza el campo de tama\u00f1o de fragmento de la codificaci\u00f3n de transferencia fragmentada HTTP utilizando std::strtoul(). Seg\u00fan el est\u00e1ndar C (\u00a77.22.1.4), strtoul acepta silenciosamente un signo menos inicial, realizando un desbordamiento sin signo: strtoul(\u0027-2\u0027, ..., 16) devuelve ULONG_MAX ? 1 (0xFFFFFFFFFFFFFFFE). La \u00fanica protecci\u00f3n de la biblioteca (l\u00ednea 12833) rechaza ULONG_MAX (el resultado de \u0027-1\u0027), pero cualquier otro valor negativo como \u0027-2\u0027 pasa la validaci\u00f3n. El valor casi m\u00e1ximo resultante se almacena en chunk_remaining y controla cu\u00e1ntos bytes el bucle de lectura del servidor consume de la red. Esta vulnerabilidad est\u00e1 corregida en la 0.43.4."
    }
  ],
  "id": "CVE-2026-45352",
  "lastModified": "2026-07-22T06:10:00.170",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "LOW",
          "baseScore": 5.3,
          "baseSeverity": "MEDIUM",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 1.4,
        "source": "security-advisories@github.com",
        "type": "Secondary"
      },
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 7.5,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "NONE",
          "integrityImpact": "NONE",
          "privilegesRequired": "NONE",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 3.9,
        "impactScore": 3.6,
        "source": "nvd@nist.gov",
        "type": "Primary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-45352",
          "options": [
            {
              "exploitation": "poc"
            },
            {
              "automatable": "yes"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-06-02T01:51:40.756562Z",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-05-29T20:16:26.140",
  "references": [
    {
      "source": "security-advisories@github.com",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8"
    },
    {
      "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
      "tags": [
        "Exploit",
        "Vendor Advisory"
      ],
      "url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8"
    }
  ],
  "sourceIdentifier": "security-advisories@github.com",
  "vulnStatus": "Modified",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-20"
        },
        {
          "lang": "en",
          "value": "CWE-770"
        },
        {
          "lang": "en",
          "value": "CWE-1285"
        }
      ],
      "source": "security-advisories@github.com",
      "type": "Secondary"
    }
  ]
}