CVE-2026-69244: AIOHTTP Out-of-bounds Heap Read Vulnerability

HIGH
Advisory Identifier: GHSA-cq5v-8q36-5273
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CWE-125 CWE-400 CWE-416
Published
Advisory Summary

CVE-2026-69244 is a HIGH out-of-bounds heap read vulnerability (CWE-125: Out-of-bounds Read) affecting AIOHTTP libraries in the PyPI ecosystem. The issue involves out-of-bounds heap read in c http response parser error path (malformed chunked response). Remediation is available by upgrading affected packages to version 3.14.3.

CVE-2026-69244 at a Glance

CVE Identifier CVE-2026-69244
GHSA Identifier GHSA-cq5v-8q36-5273
Severity HIGH
CVSS v3.1 Base Score N/A
CWE Classification CWE-125: Out-of-bounds Read
Affected Product AIOHTTP
Package Ecosystem PyPI
Published Date
Last Updated

How to Fix CVE-2026-69244

To remediate this vulnerability, upgrade all affected AIOHTTP dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

aiohttp fixed: 3.14.3 
pip install aiohttp>=3.14.3
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

pip show aiohttp

How to Check if You Are Affected

To determine whether your Python environment is affected by CVE-2026-69244, inspect your installed packages using pip:

pip show aiohttp

Analyze the terminal output to locate any version of AIOHTTP in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 3.14.3), your application is affected.

Note: The pip show aiohttp command checks currently installed packages in your active Python environment.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-125: Out-of-bounds Read, where the product reads data past the end, or before the beginning, of the intended buffer. In AIOHTTP, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Summary An out-of-bounds heap read could occur in the C response parser while building an error message for a malformed response. ### Impact An attacker controlled server, or possibly an accidental response could trigger a DoS in the client. ### Workaround If unable to upgrade, the Python parser is unaffected and can be used with `AIOHTTP_NO_EXTENSIONS=1`. --- Patch: https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d

CVE-2026-69244 Affected AIOHTTP Versions

1 component(s)
Fixed Versions:
3.14.3
Product / Package Ecosystem Affected Versions Fixed Version
aiohttp
pypi/aiohttp
PyPI
< 3.14.3
3.14.3

References

GitHub Advisory / Wiki ADVISORY
https://github.com/aio-libs/aiohttp/security/advisories/GHSA-cq5v-8q36-5273
AIOHTTP Source Repository REPOSITORY
https://github.com/aio-libs/aiohttp/pull/13223
Security Fix Commit FIX COMMIT
https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d
AIOHTTP Source Repository REPOSITORY
https://github.com/aio-libs/aiohttp
AIOHTTP Release RELEASE
https://github.com/aio-libs/aiohttp/releases/tag/v3.14.3

Frequently Asked Questions

What is CVE-2026-69244?
CVE-2026-69244 is a security vulnerability in AIOHTTP involving Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response) under CWE-125: Out-of-bounds Read.
Which AIOHTTP versions are affected?
Affected versions include releases prior to 3.14.3 across affected packages: aiohttp.
What version fixes CVE-2026-69244?
Upgrading to 3.14.3 (or the latest patched release for your respective branch) resolves the vulnerability.
Is aiohttp affected?
Yes, aiohttp is affected in releases prior to 3.14.3. Upgrade your dependency to 3.14.3 or later.
What CWE is associated with CVE-2026-69244?
CVE-2026-69244 is classified under CWE-125: Out-of-bounds Read (The product reads data past the end, or before the beginning, of the intended buffer.).
How can I check PyPI dependencies for CVE-2026-69244?
Run the dependency tree command: 'pip show aiohttp'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-cq5v-8q36-5273",
  "modified" : "2026-08-03T20:51:13Z",
  "published" : "2026-08-03T20:51:13Z",
  "aliases" : [ "CVE-2026-69244" ],
  "summary" : "AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)",
  "details" : "### Summary\n\nAn out-of-bounds heap read could occur in the C response parser while building an error message for a malformed response.\n\n### Impact\n\nAn attacker controlled server, or possibly an accidental response could trigger a DoS in the client.\n\n### Workaround\n\nIf unable to upgrade, the Python parser is unaffected and can be used with `AIOHTTP_NO_EXTENSIONS=1`.\n\n---\n\nPatch: https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d",
  "severity" : [ {
    "type" : "CVSS_V4",
    "score" : "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "PyPI",
      "name" : "aiohttp"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "0"
      }, {
        "fixed" : "3.14.3"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 3.14.2"
    }
  } ],
  "references" : [ {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/security/advisories/GHSA-cq5v-8q36-5273"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/pull/13223"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/aio-libs/aiohttp"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/aio-libs/aiohttp/releases/tag/v3.14.3"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-125", "CWE-400", "CWE-416" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2026-08-03T20:51:13Z",
    "nvd_published_at" : null
  }
}