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.

CVSS 4.0

7.1CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

EPSS

0.5% chance of exploitation in the next 30 days; higher than 44% of CVEs (scores of 2026-10-25)

CWEs

CWE-125, CWE-400, CWE-416

Published

2026-08-03

Modified

2026-10-23

Record from

the NVD, synced 2026-10-24

Packages (OSV)

References

• https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d
• https://github.com/aio-libs/aiohttp/pull/13223
• https://github.com/aio-libs/aiohttp/releases/tag/v3.14.3
• https://github.com/aio-libs/aiohttp/security/advisories/GHSA-cq5v-8q36-5273

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