python-anyio — security advisory

{
  "id": "65f9ba32236d457bfa6d57d52b592bbc7ca61b122b1ae31205a5f8bb970293eb",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-63374",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-63374",
    "summary": "AnyIO is a high level asynchronous concurrency and networking framework that works on top of either Trio or asyncio. Prior to 4.14.2, connect_tcp() and TLSStream.wrap() can validate internationalized host names after the standard library converts them with IDNA 2003 instead of IDNA 2008. When a connection to a non-ASCII domain is hijacked or redirected, an attacker can obtain a legitimate certificate for the different ASCII hostname produced by IDNA 2003 and present it to the client, causing the malicious endpoint's certificate to validate. This issue is fixed in version 4.14.2.",
    "evidence": "osv:UBUNTU-CVE-2026-63374",
    "products": [
      {
        "name": {
          "value": "python-anyio",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.0.2-2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "3.5.0-2ubuntu1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "3.5.0-3ubuntu2",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-anyio",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "3.7.0-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "4.2.0-1",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-anyio",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "4.11.0-3",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "4.12.1-2",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "4.12.1-3",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "4.15.1-3",
            "evidence": "/affected/2/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-anyio",
          "evidence": "/affected/3/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "4.8.0-3",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "4.11.0-2",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "4.11.0-3",
            "evidence": "/affected/3/versions"
          }
        ]
      }
    ],
    "severity": "critical",
    "structured": {
      "id": "UBUNTU-CVE-2026-63374",
      "aliases": [
        "UBUNTU-CVE-2026-63374"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "python-anyio",
            "purl": "pkg:deb/ubuntu/python-anyio?arch=source&distro=jammy",
            "ecosystem": "Ubuntu:22.04:LTS"
          },
          "versions": [
            "2.0.2-2",
            "3.5.0-2ubuntu1",
            "3.5.0-3ubuntu2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63374.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-anyio",
                "binary_version": "3.5.0-3ubuntu2"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "python-anyio",
            "purl": "pkg:deb/ubuntu/python-anyio?arch=source&distro=noble",
            "ecosystem": "Ubuntu:24.04:LTS"
          },
          "versions": [
            "3.7.0-1",
            "4.2.0-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63374.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-anyio",
                "binary_version": "4.2.0-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "python-anyio",
            "purl": "pkg:deb/ubuntu/python-anyio?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "4.11.0-3",
            "4.12.1-2",
            "4.12.1-3",
            "4.15.1-3"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63374.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-anyio",
                "binary_version": "4.15.1-3"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "python-anyio",
            "purl": "pkg:deb/ubuntu/python-anyio?arch=source&distro=resolute",
            "ecosystem": "Ubuntu:26.04:LTS"
          },
          "versions": [
            "4.8.0-3",
            "4.11.0-2",
            "4.11.0-3"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-63374.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-anyio",
                "binary_version": "4.11.0-3"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T13:00:32.612280190Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-63374"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-63374",
        "https://www.cve.org/CVERecord?id=CVE-2026-63374",
        "https://github.com/agronholm/anyio/security/advisories/GHSA-82r6-8w77-94w6"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-63374",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 360688,
  "published_at": "2026-09-22T16:17:00+00:00"
}