AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)
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
Affected software
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| Platform | Package | Vulnerable versions | Fixed in |
|---|---|---|---|
| Python (PyPI) | aiohttp | < 3.14.3 | 3.14.3 |
References
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-cq5v-8q36-5273
- https://github.com/aio-libs/aiohttp/pull/13223
- https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d
- https://github.com/aio-libs/aiohttp
- https://github.com/aio-libs/aiohttp/releases/tag/v3.14.3
- https://pypi.org/project/aiohttp
- https://github.com/advisories/GHSA-cq5v-8q36-5273
- https://nvd.nist.gov/vuln/detail/CVE-2026-69244
- CVSS vector
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- Weakness (CWE)
CWE-125, CWE-400, CWE-416- Platform
- Python (PyPI)
- Package
aiohttp- Disclosed
- 03.08.2026
- Updated
- 11.10.2026 15:18
Sources and licenses
OSV / GitHub Advisory Database - PYSEC-2026-3545 - PyPA Advisory Database; CC BY 4.0
OSV / GitHub Advisory Database - GHSA-cq5v-8q36-5273 - CC BY 4.0
Vulnerability history: aiohttp
All published vulnerabilities of this package (Python (PyPI)), newest first. Shows whether this is a one-off slip or a package that needs watching.
- Total entries
- 55
- First → latest
- 02.2021 10.2026
- Without a fix
- 0
- Exploited in attacks
- 0
Severity breakdown
- High 7
- Medium 29
- Low 19
Disclosures per year
- 2021: 1
- 2022: 0
- 2023: 6
- 2024: 7
- 2025: 1
- 2026: 40
-
AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response) this entry
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