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PYSEC-2026-3545
AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)
Quick fix
PYSEC-2026-3545 — aiohttp: upgrade to the fixed version with the command below.
pip install --upgrade 'aiohttp>=3.14.3'Details
### 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`.
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Patch: https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d
Are you affected?
Enter the version of the package you're using.
Affected packages
References
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-cq5v-8q36-5273[WEB]
- https://github.com/aio-libs/aiohttp/pull/13223[WEB]
- https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d[WEB]
- https://github.com/aio-libs/aiohttp[PACKAGE]
- https://github.com/aio-libs/aiohttp/releases/tag/v3.14.3[WEB]
- https://pypi.org/project/aiohttp[PACKAGE]
- https://github.com/advisories/GHSA-cq5v-8q36-5273[ADVISORY]
- https://nvd.nist.gov/vuln/detail/CVE-2026-69244[ADVISORY]