Vulnerability-Lookup

ubuntu-cve-2025-43859

Vulnerability from osv_ubuntu

Published

2025-04-24 19:15

Modified

2026-01-20 05:33

Summary

Details

h11 is a Python implementation of HTTP/1.1. Prior to version 0.16.0, a leniency in h11's parsing of line terminators in chunked-coding message bodies can lead to request smuggling vulnerabilities under certain conditions. This issue has been patched in version 0.16.0. Since exploitation requires the combination of buggy h11 with a buggy (reverse) proxy, fixing either component is sufficient to mitigate this issue.

Severity

9.1 (Critical)


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

N/A (UNKNOWN)


                    
                      medium

References

URL

Type

	https://ubuntu.com/security/CVE-2025-43859	REPORT
	https://www.cve.org/CVERecord?id=CVE-2025-43859	REPORT
	https://github.com/python-hyper/h11/security/advi…	REPORT
	https://github.com/python-hyper/h11/commit/114803…	REPORT
	https://ubuntu.com/security/notices/USN-7503-1	ADVISORY

JSON

To clipboard

{
  "affected": [
    {
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-h11",
            "binary_version": "0.14.0-1ubuntu0.24.04.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "python-h11",
        "purl": "pkg:deb/ubuntu/python-h11@0.14.0-1ubuntu0.24.04.1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.14.0-1ubuntu0.24.04.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.14.0-1"
      ]
    }
  ],
  "aliases": [],
  "details": "h11 is a Python implementation of HTTP/1.1. Prior to version 0.16.0, a leniency in h11\u0027s parsing of line terminators in chunked-coding message bodies can lead to request smuggling vulnerabilities under certain conditions. This issue has been patched in version 0.16.0. Since exploitation requires the combination of buggy h11 with a buggy (reverse) proxy, fixing either component is sufficient to mitigate this issue.",
  "id": "UBUNTU-CVE-2025-43859",
  "modified": "2026-01-20T05:33:06Z",
  "published": "2025-04-24T19:15:00Z",
  "references": [
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-43859"
    },
    {
      "type": "REPORT",
      "url": "https://www.cve.org/CVERecord?id=CVE-2025-43859"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/python-hyper/h11/security/advisories/GHSA-vqfr-h8mv-ghfj"
    },
    {
      "type": "REPORT",
      "url": "https://github.com/python-hyper/h11/commit/114803a29ce50116dc47951c690ad4892b1a36ed"
    },
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-7503-1"
    }
  ],
  "related": [
    "USN-7503-1"
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
      "type": "CVSS_V3"
    },
    {
      "score": "medium",
      "type": "Ubuntu"
    }
  ],
  "upstream": [
    "CVE-2025-43859"
  ]
}

CVE-2025-43859 (GCVE-0-2025-43859)

Vulnerability from cvelistv5 – Published: 2025-04-24 18:15 – Updated: 2025-04-24 19:02

Title

h11 accepts some malformed Chunked-Encoding bodies

Summary

Severity

9.1 (Critical)


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

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator (v2.0.3)

CWE

CWE-444 - Inconsistent Interpretation of HTTP Requests ('HTTP Request/Response Smuggling')

Assigner

GitHub_M

References

2 references

URL	Tags
https://github.com/python-hyper/h11/security/advi…	x_refsource_CONFIRM
https://github.com/python-hyper/h11/commit/114803…	x_refsource_MISC

Impacted products

1 product

Vendor	Product	Version
python-hyper	h11	Affected: < 0.16.0

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2025-43859",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2025-04-24T19:02:05.000674Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2025-04-24T19:02:45.130Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "h11",
          "vendor": "python-hyper",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 0.16.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "h11 is a Python implementation of HTTP/1.1. Prior to version 0.16.0, a leniency in h11\u0027s parsing of line terminators in chunked-coding message bodies can lead to request smuggling vulnerabilities under certain conditions. This issue has been patched in version 0.16.0. Since exploitation requires the combination of buggy h11 with a buggy (reverse) proxy, fixing either component is sufficient to mitigate this issue."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 9.1,
            "baseSeverity": "CRITICAL",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-444",
              "description": "CWE-444: Inconsistent Interpretation of HTTP Requests (\u0027HTTP Request/Response Smuggling\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2025-04-24T18:15:53.328Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/python-hyper/h11/security/advisories/GHSA-vqfr-h8mv-ghfj",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/python-hyper/h11/security/advisories/GHSA-vqfr-h8mv-ghfj"
        },
        {
          "name": "https://github.com/python-hyper/h11/commit/114803a29ce50116dc47951c690ad4892b1a36ed",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/python-hyper/h11/commit/114803a29ce50116dc47951c690ad4892b1a36ed"
        }
      ],
      "source": {
        "advisory": "GHSA-vqfr-h8mv-ghfj",
        "discovery": "UNKNOWN"
      },
      "title": "h11 accepts some malformed Chunked-Encoding bodies"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2025-43859",
    "datePublished": "2025-04-24T18:15:53.328Z",
    "dateReserved": "2025-04-17T20:07:08.556Z",
    "dateUpdated": "2025-04-24T19:02:45.130Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.1"
}

usn-7503-1

Vulnerability from osv_ubuntu

Published

2025-05-08 10:53

Modified

2026-02-10 04:48

Summary

python-h11 vulnerability

Details

Jeppe Bonde Weikop discovered that h11 incorrectly handled crafted HTTP requests. A remote attacker could possibly use this issue to smuggle malicious HTTP requests, which could potentially lead to security control bypass and information leakage.

References

URL

Type

	https://ubuntu.com/security/notices/USN-7503-1	ADVISORY
	https://ubuntu.com/security/CVE-2025-43859	REPORT

JSON

To clipboard

{
  "affected": [
    {
      "database_specific": {
        "cves_map": {
          "cves": [
            {
              "id": "CVE-2025-43859",
              "severity": [
                {
                  "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N",
                  "type": "CVSS_V3"
                },
                {
                  "score": "medium",
                  "type": "Ubuntu"
                }
              ]
            }
          ],
          "ecosystem": "Ubuntu:24.04:LTS"
        }
      },
      "ecosystem_specific": {
        "availability": "No subscription required",
        "binaries": [
          {
            "binary_name": "python3-h11",
            "binary_version": "0.14.0-1ubuntu0.24.04.1"
          }
        ]
      },
      "package": {
        "ecosystem": "Ubuntu:24.04:LTS",
        "name": "python-h11",
        "purl": "pkg:deb/ubuntu/python-h11@0.14.0-1ubuntu0.24.04.1?arch=source\u0026distro=noble"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0.14.0-1ubuntu0.24.04.1"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ],
      "versions": [
        "0.14.0-1"
      ]
    }
  ],
  "aliases": [],
  "details": "Jeppe Bonde Weikop discovered that h11 incorrectly handled crafted HTTP\nrequests. A remote attacker could possibly use this issue to smuggle\nmalicious HTTP requests, which could potentially lead to security\ncontrol bypass and information leakage.",
  "id": "USN-7503-1",
  "modified": "2026-02-10T04:48:36Z",
  "published": "2025-05-08T10:53:58Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://ubuntu.com/security/notices/USN-7503-1"
    },
    {
      "type": "REPORT",
      "url": "https://ubuntu.com/security/CVE-2025-43859"
    }
  ],
  "related": [],
  "schema_version": "1.7.0",
  "summary": "python-h11 vulnerability",
  "upstream": [
    "UBUNTU-CVE-2025-43859"
  ]
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
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.

Detection rules are retrieved from Rulezet.

Action not permitted

ubuntu-cve-2025-43859

Vulnerability from osv_ubuntu

CVE-2025-43859 (GCVE-0-2025-43859)

usn-7503-1

Vulnerability from osv_ubuntu

Tags

Sightings

Nomenclature