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python-aiohttp — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-CVE-2026-34525

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

Products
python-aiohttp
Affected versions
0.17.2-1, 0.17.4-1, 0.17.4-1build1, 0.20.2-1, 0.20.2-1ubuntu0.1~esm1, 2.2.3-1build1, 2.2.3-2, 2.3.6-1, 3.0.1-1, 3.0.1-1ubuntu0.1~esm1, 3.0.1-1ubuntu0.1~esm4, 3.0.1-1ubuntu0.1~esm5, 3.0.1-1ubuntu0.1~esm6, 3.0.1-1ubuntu0.1~esm7, 3.10.11-1build1, 3.11.16-1, 3.11.16-1ubuntu0.1, 3.13.1-1, 3.13.3-3, 3.13.3-3ubuntu1, 3.13.3-3ubuntu1+esm1, 3.14.1-4, 3.14.1-5, 3.14.3-1, 3.5.4-1, 3.5.4-1build1, 3.6.1-1, 3.6.2-1, 3.6.2-1build1, 3.6.2-1ubuntu0.1~esm1, 3.6.2-1ubuntu1, 3.6.2-1ubuntu1+esm1, 3.6.2-1ubuntu1+esm3, 3.6.2-1ubuntu1+esm4, 3.6.2-1ubuntu1+esm5, 3.6.2-1ubuntu1+esm6, 3.7.4-1, 3.7.4-1build2, 3.8.1-3, 3.8.1-4, 3.8.1-4build1, 3.8.1-4ubuntu0.2, 3.8.1-4ubuntu0.2+esm1, 3.8.1-4ubuntu0.2+esm2, 3.8.1-4ubuntu0.2+esm3, 3.8.4-1, 3.9.1-1, 3.9.1-1build1, 3.9.1-1ubuntu0.1, 3.9.1-1ubuntu0.1+esm1, 3.9.1-1ubuntu0.1+esm2, 3.9.1-1ubuntu0.1+esm3
Fixed versions
Not specified
CVEs
CVE-2026-34525
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 03:00 UTC · Revision 1

Source evidence

UBUNTU-CVE-2026-34525

core-osv · Original source

Published 1 Apr 2026, 21:17 UTC

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.

osv:UBUNTU-CVE-2026-34525

python-aiohttp

Fixed versions: Not specified

python-aiohttp

Fixed versions: Not specified

python-aiohttp

Fixed versions: Not specified

python-aiohttp

Fixed versions: Not specified

python-aiohttp

Fixed versions: Not specified

python-aiohttp

Fixed versions: Not specified

python-aiohttp

Fixed versions: Not specified

python-aiohttp

Fixed versions: Not specified

Complete source record
{
  "id": "6680282a9b6fe685e58e1443f98e65efe6cf2d5e1316bca9ecb4197d19d61ac2",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-34525",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-34525",
    "summary": "AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to version 3.13.4, multiple Host headers were allowed in aiohttp. This issue has been patched in version 3.13.4.",
    "evidence": "osv:UBUNTU-CVE-2026-34525",
    "products": [
      {
        "name": {
          "value": "python-aiohttp",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "0.17.2-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.17.4-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.17.4-1build1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.20.2-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "0.20.2-1ubuntu0.1~esm1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-aiohttp",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2.2.3-1build1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.2.3-2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2.3.6-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "3.0.1-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "3.0.1-1ubuntu0.1~esm1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "3.0.1-1ubuntu0.1~esm4",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "3.0.1-1ubuntu0.1~esm5",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "3.0.1-1ubuntu0.1~esm6",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "3.0.1-1ubuntu0.1~esm7",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-aiohttp",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "3.5.4-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.5.4-1build1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.1-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1build1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1ubuntu0.1~esm1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1ubuntu1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1ubuntu1+esm1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1ubuntu1+esm3",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1ubuntu1+esm4",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1ubuntu1+esm5",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "3.6.2-1ubuntu1+esm6",
            "evidence": "/affected/2/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-aiohttp",
          "evidence": "/affected/3/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "3.7.4-1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "3.7.4-1build2",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "3.8.1-3",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "3.8.1-4",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "3.8.1-4build1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "3.8.1-4ubuntu0.2",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "3.8.1-4ubuntu0.2+esm1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "3.8.1-4ubuntu0.2+esm2",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "3.8.1-4ubuntu0.2+esm3",
            "evidence": "/affected/3/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-aiohttp",
          "evidence": "/affected/4/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "3.8.4-1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "3.9.1-1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "3.9.1-1build1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "3.9.1-1ubuntu0.1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "3.9.1-1ubuntu0.1+esm1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "3.9.1-1ubuntu0.1+esm2",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "3.9.1-1ubuntu0.1+esm3",
            "evidence": "/affected/4/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-aiohttp",
          "evidence": "/affected/5/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "3.10.11-1build1",
            "evidence": "/affected/5/versions"
          },
          {
            "value": "3.11.16-1",
            "evidence": "/affected/5/versions"
          },
          {
            "value": "3.11.16-1ubuntu0.1",
            "evidence": "/affected/5/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-aiohttp",
          "evidence": "/affected/6/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "3.13.3-3ubuntu1",
            "evidence": "/affected/6/versions"
          },
          {
            "value": "3.14.1-4",
            "evidence": "/affected/6/versions"
          },
          {
            "value": "3.14.1-5",
            "evidence": "/affected/6/versions"
          },
          {
            "value": "3.14.3-1",
            "evidence": "/affected/6/versions"
          }
        ]
      },
      {
        "name": {
          "value": "python-aiohttp",
          "evidence": "/affected/7/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "3.11.16-1",
            "evidence": "/affected/7/versions"
          },
          {
            "value": "3.13.1-1",
            "evidence": "/affected/7/versions"
          },
          {
            "value": "3.13.3-3",
            "evidence": "/affected/7/versions"
          },
          {
            "value": "3.13.3-3ubuntu1",
            "evidence": "/affected/7/versions"
          },
          {
            "value": "3.13.3-3ubuntu1+esm1",
            "evidence": "/affected/7/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-34525",
      "aliases": [
        "UBUNTU-CVE-2026-34525"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:N/VI:L/VA:N/SC:L/SI:L/SA:N"
        },
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "python-aiohttp",
            "purl": "pkg:deb/ubuntu/python-aiohttp?arch=source&distro=esm-apps-legacy%2Fxenial",
            "ecosystem": "Ubuntu:Pro:16.04:LTS"
          },
          "versions": [
            "0.17.2-1",
            "0.17.4-1",
            "0.17.4-1build1",
            "0.20.2-1",
            "0.20.2-1ubuntu0.1~esm1"
          ],
          "database_specific": {
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          },
          "ecosystem_specific": {
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            "purl": "pkg:deb/ubuntu/python-aiohttp?arch=source&distro=esm-apps%2Fbionic",
            "ecosystem": "Ubuntu:Pro:18.04:LTS"
          },
          "versions": [
            "2.2.3-1build1",
            "2.2.3-2",
            "2.3.6-1",
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            "3.0.1-1ubuntu0.1~esm1",
            "3.0.1-1ubuntu0.1~esm4",
            "3.0.1-1ubuntu0.1~esm5",
            "3.0.1-1ubuntu0.1~esm6",
            "3.0.1-1ubuntu0.1~esm7"
          ],
          "database_specific": {
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          },
          "ecosystem_specific": {
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          },
          "versions": [
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            "3.5.4-1build1",
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            "3.6.2-1ubuntu1",
            "3.6.2-1ubuntu1+esm1",
            "3.6.2-1ubuntu1+esm3",
            "3.6.2-1ubuntu1+esm4",
            "3.6.2-1ubuntu1+esm5",
            "3.6.2-1ubuntu1+esm6"
          ],
          "database_specific": {
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          },
          "ecosystem_specific": {
            "binaries": [
              {
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                "binary_version": "3.6.2-1ubuntu1+esm6"
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            ]
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        },
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            "purl": "pkg:deb/ubuntu/python-aiohttp?arch=source&distro=esm-apps%2Fjammy",
            "ecosystem": "Ubuntu:Pro:22.04:LTS"
          },
          "versions": [
            "3.7.4-1",
            "3.7.4-1build2",
            "3.8.1-3",
            "3.8.1-4",
            "3.8.1-4build1",
            "3.8.1-4ubuntu0.2",
            "3.8.1-4ubuntu0.2+esm1",
            "3.8.1-4ubuntu0.2+esm2",
            "3.8.1-4ubuntu0.2+esm3"
          ],
          "database_specific": {
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          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-aiohttp",
                "binary_version": "3.8.1-4ubuntu0.2+esm3"
              }
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        },
        {
          "ranges": [
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          ],
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            "purl": "pkg:deb/ubuntu/python-aiohttp?arch=source&distro=esm-apps%2Fnoble",
            "ecosystem": "Ubuntu:Pro:24.04:LTS"
          },
          "versions": [
            "3.8.4-1",
            "3.9.1-1",
            "3.9.1-1build1",
            "3.9.1-1ubuntu0.1",
            "3.9.1-1ubuntu0.1+esm1",
            "3.9.1-1ubuntu0.1+esm2",
            "3.9.1-1ubuntu0.1+esm3"
          ],
          "database_specific": {
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          },
          "ecosystem_specific": {
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          ],
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            "purl": "pkg:deb/ubuntu/python-aiohttp?arch=source&distro=questing",
            "ecosystem": "Ubuntu:25.10"
          },
          "versions": [
            "3.10.11-1build1",
            "3.11.16-1",
            "3.11.16-1ubuntu0.1"
          ],
          "database_specific": {
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          },
          "ecosystem_specific": {
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            ]
          }
        },
        {
          "ranges": [
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              "type": "ECOSYSTEM",
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                {
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              ]
            }
          ],
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            "purl": "pkg:deb/ubuntu/python-aiohttp?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "3.13.3-3ubuntu1",
            "3.14.1-4",
            "3.14.1-5",
            "3.14.3-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34525.json"
          },
          "ecosystem_specific": {
            "binaries": [
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              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
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                }
              ]
            }
          ],
          "package": {
            "name": "python-aiohttp",
            "purl": "pkg:deb/ubuntu/python-aiohttp?arch=source&distro=esm-apps%2Fresolute",
            "ecosystem": "Ubuntu:Pro:26.04:LTS"
          },
          "versions": [
            "3.11.16-1",
            "3.13.1-1",
            "3.13.3-3",
            "3.13.3-3ubuntu1",
            "3.13.3-3ubuntu1+esm1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-34525.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "python3-aiohttp",
                "binary_version": "3.13.3-3ubuntu1+esm1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T13:00:01.370881907Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-34525"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-34525",
        "https://www.cve.org/CVERecord?id=CVE-2026-34525",
        "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-c427-h43c-vf67",
        "https://github.com/aio-libs/aiohttp/commit/53e2e6fc58b89c6185be7820bd2c9f40216b3000",
        "https://github.com/aio-libs/aiohttp/commit/e00ca3cca92c465c7913c4beb763a72da9ed8349",
        "https://github.com/aio-libs/aiohttp/releases/tag/v3.13.4"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-34525",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 360137,
  "published_at": "2026-04-01T21:17:00+00:00"
}