Vulnerability-Lookup

UBUNTU-CVE-2026-45352 (CVE-2026-45352)

Vulnerability from osv_ubuntu – Published: 2026-05-29 20:16 – Updated: 2026-06-25 11:18 – Source website

Details

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.

Severity

5.3 (Medium)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

7.5 (High)


                    
                      CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2026-45352	REPORT
	https://www.cve.org/CVERecord?id=CVE-2026-45352	REPORT
	https://github.com/yhirose/cpp-httplib/security/a…	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcpp-httplib0",
            "binary_version": "0.10.3+ds-1ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:22.04:LTS",
        "name": "cpp-httplib",
        "purl": "pkg:deb/ubuntu/cpp-httplib@0.10.3+ds-1ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/jammy"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.9.9+ds-1",
        "0.9.10+ds-1",
        "0.10.1+ds-1",
        "0.10.2+ds-1",
        "0.10.3+ds-1",
        "0.10.3+ds-1ubuntu0.1~esm1",
        "0.10.3+ds-1ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcpp-httplib0.14t64",
            "binary_version": "0.14.3+ds-1.1ubuntu0.1~esm2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:24.04:LTS",
        "name": "cpp-httplib",
        "purl": "pkg:deb/ubuntu/cpp-httplib@0.14.3+ds-1.1ubuntu0.1~esm2?arch=source\u0026distro=esm-apps/noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.13.1+ds-1ubuntu1",
        "0.14.3+ds-1",
        "0.14.3+ds-1.1",
        "0.14.3+ds-1.1build1",
        "0.14.3+ds-1.1build2",
        "0.14.3+ds-1.1ubuntu0.1~esm1",
        "0.14.3+ds-1.1ubuntu0.1~esm2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcpp-httplib0.18",
            "binary_version": "0.18.7-1ubuntu0.25.10.2"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:25.10",
        "name": "cpp-httplib",
        "purl": "pkg:deb/ubuntu/cpp-httplib@0.18.7-1ubuntu0.25.10.2?arch=source\u0026distro=questing"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.18.7-1",
        "0.18.7-1ubuntu0.25.10.1",
        "0.18.7-1ubuntu0.25.10.2"
      ]
    },
    {
      "ecosystem_specific": {
        "binaries": [
          {
            "binary_name": "libcpp-httplib0.26",
            "binary_version": "0.26.0+ds-2ubuntu3+esm1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:Pro:26.04:LTS",
        "name": "cpp-httplib",
        "purl": "pkg:deb/ubuntu/cpp-httplib@0.26.0+ds-2ubuntu3+esm1?arch=source\u0026distro=esm-apps/resolute"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.18.7-1",
        "0.26.0+ds-2ubuntu2",
        "0.26.0+ds-2ubuntu3",
        "0.26.0+ds-2ubuntu3+esm1"
      ]
    }
  ],
  "aliases": [],
  "details": "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.",
  "id": "UBUNTU-CVE-2026-45352",
  "modified": "2026-06-25T11:18:14Z",
  "published": "2026-05-29T20:16:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2026-45352"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2026-45352"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L",
      "type": "CVSS_V3"
    },
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2026-45352"
  ]
}

CVE-2026-45352 (GCVE-0-2026-45352)

Vulnerability from cvelistv5 – Published: 2026-05-29 19:14 – Updated: 2026-06-02 01:52

Title

cpp-httplib DoS: Negative chunk-size in chunked Transfer-Encoding

Summary

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

SSVC

Exploitation: poc Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-02 01:51 UTC

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

Assigner

GitHub_M mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/yhirose/cpp-httplib/security/a…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
yhirose	cpp-httplib	Affected: < 0.43.4

Show details on NVD website

JSON

To clipboard

{
  "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": [
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            ],
            "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": [
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              "lang": "en",
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              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-770",
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              "lang": "en",
              "type": "CWE"
            }
          ]
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      "providerMetadata": {
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          "tags": [
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          "url": "https://github.com/yhirose/cpp-httplib/security/advisories/GHSA-h6wq-j5mv-f3q8"
        }
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      "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",
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    "datePublished": "2026-05-29T19:14:08.065Z",
    "dateReserved": "2026-05-11T21:40:08.178Z",
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    "state": "PUBLISHED"
  },
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}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
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UBUNTU-CVE-2026-45352 (CVE-2026-45352)

CVE-2026-45352 (GCVE-0-2026-45352)

Tags

Sightings

Nomenclature

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