CVE-2026-45352 (GCVE-0-2026-45352)
Vulnerability from cvelistv5
Published
2026-05-29 19:14
Modified
2026-06-02 01:52
CWE
  • CWE-20 - Improper Input Validation
  • CWE-1285 - Improper Validation of Specified Index, Position, or Offset in Input
  • CWE-770 - Allocation of Resources Without Limits or Throttling
Summary
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 (§7.22.1.4), strtoul silently accepts a leading minus sign, performing unsigned wrap-around: strtoul("-2", …, 16) returns ULONG_MAX − 1 (0xFFFFFFFFFFFFFFFE). The library's 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's read loop consumes from the network. This vulnerability is fixed in 0.43.4.
Impacted products
Vendor Product Version
yhirose cpp-httplib Version: < 0.43.4
Create a notification for this product.
Show details on NVD website


{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-45352",
                "options": [
                  {
                    "Exploitation": "poc"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-02T01:51:40.756562Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-02T01:52:12.106Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "references": [
          {
            "tags": [
              "exploit"
            ],
            "url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8"
          }
        ],
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "cpp-httplib",
          "vendor": "yhirose",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.43.4"
            }
          ]
        }
      ],
      "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."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "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"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-20",
              "description": "CWE-20: Improper Input Validation",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-1285",
              "description": "CWE-1285: Improper Validation of Specified Index, Position, or Offset in Input",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
              "description": "CWE-770: Allocation of Resources Without Limits or Throttling",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-29T19:15:42.208Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8"
        }
      ],
      "source": {
        "advisory": "GHSA-h6wq-j5mv-f3q8",
        "discovery": "UNKNOWN"
      },
      "title": "cpp-httplib DoS: Negative chunk-size in chunked Transfer-Encoding"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45352",
    "datePublished": "2026-05-29T19:14:08.065Z",
    "dateReserved": "2026-05-11T21:40:08.178Z",
    "dateUpdated": "2026-06-02T01:52:12.106Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "vulnrichment": {
      "containers": "{\"adp\": [{\"title\": \"CISA ADP Vulnrichment\", \"metrics\": [{\"other\": {\"type\": \"ssvc\", \"content\": {\"id\": \"CVE-2026-45352\", \"role\": \"CISA Coordinator\", \"options\": [{\"Exploitation\": \"poc\"}, {\"Automatable\": \"yes\"}, {\"Technical Impact\": \"partial\"}], \"version\": \"2.0.3\", \"timestamp\": \"2026-06-02T01:51:40.756562Z\"}}}], \"references\": [{\"url\": \"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8\", \"tags\": [\"exploit\"]}], \"providerMetadata\": {\"orgId\": \"134c704f-9b21-4f2e-91b3-4a467353bcc0\", \"shortName\": \"CISA-ADP\", \"dateUpdated\": \"2026-06-02T01:52:05.190Z\"}}], \"cna\": {\"title\": \"cpp-httplib DoS: Negative chunk-size in chunked Transfer-Encoding\", \"source\": {\"advisory\": \"GHSA-h6wq-j5mv-f3q8\", \"discovery\": \"UNKNOWN\"}, \"metrics\": [{\"cvssV3_1\": {\"scope\": \"UNCHANGED\", \"version\": \"3.1\", \"baseScore\": 5.3, \"attackVector\": \"NETWORK\", \"baseSeverity\": \"MEDIUM\", \"vectorString\": \"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L\", \"integrityImpact\": \"NONE\", \"userInteraction\": \"NONE\", \"attackComplexity\": \"LOW\", \"availabilityImpact\": \"LOW\", \"privilegesRequired\": \"NONE\", \"confidentialityImpact\": \"NONE\"}}], \"affected\": [{\"vendor\": \"yhirose\", \"product\": \"cpp-httplib\", \"versions\": [{\"status\": \"affected\", \"version\": \"\u003c 0.43.4\"}]}], \"references\": [{\"url\": \"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8\", \"name\": \"https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8\", \"tags\": [\"x_refsource_CONFIRM\"]}], \"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.\"}], \"problemTypes\": [{\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-20\", \"description\": \"CWE-20: Improper Input Validation\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-1285\", \"description\": \"CWE-1285: Improper Validation of Specified Index, Position, or Offset in Input\"}]}, {\"descriptions\": [{\"lang\": \"en\", \"type\": \"CWE\", \"cweId\": \"CWE-770\", \"description\": \"CWE-770: Allocation of Resources Without Limits or Throttling\"}]}], \"providerMetadata\": {\"orgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"shortName\": \"GitHub_M\", \"dateUpdated\": \"2026-05-29T19:15:42.208Z\"}}}",
      "cveMetadata": "{\"cveId\": \"CVE-2026-45352\", \"state\": \"PUBLISHED\", \"dateUpdated\": \"2026-06-02T01:52:12.106Z\", \"dateReserved\": \"2026-05-11T21:40:08.178Z\", \"assignerOrgId\": \"a0819718-46f1-4df5-94e2-005712e83aaa\", \"datePublished\": \"2026-05-29T19:14:08.065Z\", \"assignerShortName\": \"GitHub_M\"}",
      "dataType": "CVE_RECORD",
      "dataVersion": "5.2"
    }
  }
}


Log in or create an account to share your comment.




Tags
Taxonomy of the tags.


Loading…

Loading…

Loading…

Sightings

Author Source Type Date

Nomenclature

  • Seen: The vulnerability was mentioned, discussed, or seen somewhere by the user.
  • Confirmed: The vulnerability is confirmed from an analyst perspective.
  • Published Proof of Concept: A public proof of concept is available for this vulnerability.
  • Exploited: This vulnerability was exploited and seen by the user reporting the sighting.
  • Patched: This vulnerability was successfully patched by the user reporting the sighting.
  • Not exploited: This vulnerability was not exploited or seen by the user reporting the sighting.
  • Not confirmed: The user expresses doubt about the veracity of the vulnerability.
  • Not patched: This vulnerability was not successfully patched by the user reporting the sighting.


Loading…

Loading…