AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)

Open Source Vulnerabilities CVE-2026-69244

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.

Open Source Vulnerabilities GHSA-cq5v-8q36-5273

### 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

Open Source Vulnerabilities PYSEC-2026-3545

### 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