CVE catalog

CVE-2026-69244

AIOHTTP is an asynchronous HTTP client/server…

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.3, an out-of-bounds heap read could occur in the C response parser while building an error message for a malformed response. An attacker controlled server, or possibly an accidental response, could trigger a DoS in the client. The vulnerable path was error message construction in aiohttp/_http_parser.pyx, where an llhttp error-position pointer was used to build a snippet for malformed chunked responses and malformed request or response bytes at the buffer end. This issue is fixed in version 3.14.3.

Severity: High · CVSS 7.5CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published: Aug 3, 2026, 8:50:59 PM UTC
Source: [NVD] · [CVE record]
EPSS: 0.53% · Oct 27, 2026

Projects and upstream resources

[python-aiohttp][Source-reported homepage]

Reported versions and fixes

Each observation applies to its named package, distribution, and release. Distribution backports can fix a vulnerability while retaining an older upstream version number.

Version impact has not been established. The original provider fields are retained below.

Provider details and historical evidence

Original provider fields

{
  "package_releases": [
    {
      "name": "python-aiohttp",
      "status": "fixed",
      "release": "sid",
      "version": "3.14.3-1"
    },
    {
      "name": "python-aiohttp",
      "status": "fixed",
      "release": "forky",
      "version": "3.14.3-1"
    },
    {
      "name": "python-aiohttp",
      "status": "vulnerable",
      "release": "trixie",
      "version": "3.11.16-1+deb13u1"
    },
    {
      "name": "python-aiohttp",
      "status": "vulnerable",
      "release": "trixie-security",
      "version": "3.11.16-1+deb13u1"
    },
    {
      "name": "python-aiohttp",
      "status": "not affected",
      "release": "bookworm",
      "version": "3.8.4-1+deb12u1"
    },
    {
      "name": "python-aiohttp",
      "status": "not affected",
      "release": "bookworm-security",
      "version": "3.8.4-1+deb12u1"
    }
  ],
  "fixed_versions": [
    {
      "bug": 1143597,
      "name": "python-aiohttp",
      "type": "source",
      "origin": null,
      "release": "sid",
      "urgency": "not yet assigned",
      "fixed_version": "3.14.3-1"
    },
    {
      "bug": 1143597,
      "name": "python-aiohttp",
      "type": "source",
      "origin": null,
      "release": "forky",
      "urgency": "not yet assigned",
      "fixed_version": "3.14.3-1"
    },
    {
      "bug": 1143597,
      "name": "python-aiohttp",
      "type": "source",
      "origin": null,
      "release": "trixie",
      "urgency": "not yet assigned",
      "fixed_version": ""
    },
    {
      "bug": 1143597,
      "name": "python-aiohttp",
      "type": "source",
      "origin": null,
      "release": "bookworm",
      "urgency": "unimportant",
      "fixed_version": "0"
    }
  ],
  "distribution_packages": [
    {
      "name": "aiohttp",
      "ecosystem": "pip",
      "fixed_version": "3.14.3"
    },
    {
      "name": "aiohttp",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.14.3"
            }
          ]
        }
      ],
      "ecosystem": "PyPI",
      "fixed_version": "3.14.3",
      "provider_record_id": "PYSEC-2026-3545"
    },
    {
      "name": "aiohttp",
      "ranges": [
        {
          "type": "ECOSYSTEM",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "3.14.3"
            }
          ]
        }
      ],
      "ecosystem": "PyPI",
      "fixed_version": "3.14.3",
      "provider_record_id": "GHSA-CQ5V-8Q36-5273"
    }
  ]
}

[Debian bug #1143597]

Publisher notes

[trixie] python-aiohttp: Minor issue

OpenFactory catalog packages

Matching against OpenFactory catalog package versions is in progress.

[Debian 12 (Bookworm)]

[python3-aiohttp]Unknown
Source package: [python-aiohttp]
Details (4)
- 3.8.4-1+deb12u1 · amd64 · bookworm
  Not affected
  nvd · python-aiohttp · debian · bookworm
- 3.8.4-1+deb12u1 · arm64 · bookworm
  Not affected
  nvd · python-aiohttp · debian · bookworm
- 3.8.4-1+deb12u1 · amd64 · bookworm-security
  Not affected
  nvd · python-aiohttp · debian · bookworm
- 3.8.4-1+deb12u1 · arm64 · bookworm-security
  Not affected
  nvd · python-aiohttp · debian · bookworm
[python-aiohttp-doc]Unknown
Source package: [python-aiohttp]
Details (4)
- 3.8.4-1+deb12u1 · all · bookworm
  Not affected
  nvd · python-aiohttp · debian · bookworm
- 3.8.4-1+deb12u1 · all · bookworm
  Not affected
  nvd · python-aiohttp · debian · bookworm
- 3.8.4-1+deb12u1 · all · bookworm-security
  Not affected
  nvd · python-aiohttp · debian · bookworm
- 3.8.4-1+deb12u1 · all · bookworm-security
  Not affected
  nvd · python-aiohttp · debian · bookworm

[Debian 13 (Trixie)]

[python3-aiohttp]Unknown
Source package: [python-aiohttp]
Details (4)
- 3.11.16-1+deb13u1 · amd64 · trixie
  Affected
  nvd · python-aiohttp · debian · 13
- 3.11.16-1+deb13u1 · arm64 · trixie
  Affected
  nvd · python-aiohttp · debian · 13
- 3.11.16-1+deb13u1 · amd64 · trixie-security
  Affected
  nvd · python-aiohttp · debian · 13
- 3.11.16-1+deb13u1 · arm64 · trixie-security
  Affected
  nvd · python-aiohttp · debian · 13
[python-aiohttp-doc]Unknown
Source package: [python-aiohttp]
Details (4)
- 3.11.16-1+deb13u1 · all · trixie
  Affected
  nvd · python-aiohttp · debian · 13
- 3.11.16-1+deb13u1 · all · trixie
  Affected
  nvd · python-aiohttp · debian · 13
- 3.11.16-1+deb13u1 · all · trixie-security
  Affected
  nvd · python-aiohttp · debian · 13
- 3.11.16-1+deb13u1 · all · trixie-security
  Affected
  nvd · python-aiohttp · debian · 13

Observed: Oct 27, 2026, 7:10:44 AM UTC

References

[Debian Security Tracker] · [FIRST EPSS] · [GitHub Advisory Database] · [National Vulnerability Database (NVD)] · [OSV Package Vulnerability Database] · [Red Hat security advisories and VEX] · [SUSE security advisories and VEX]