Vulnerability · Published Aug 3, 2026 · Assigned by GitHub_M
CVE-2026-69244AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response)
High 7.1
In plain English
A high-severity uncontrolled resource consumption in aiohttp from aio-libs. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 45% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:13 | python-aiohttp | no fix listed | DEBIAN-CVE-2026-69244 |
| Debian:14 | python-aiohttp | 3.14.3-1 | DEBIAN-CVE-2026-69244 |
| PyPI | aiohttp | 3.14.3 | GHSA-cq5v-8q36-5273 |
| PyPI | aiohttp | 3.14.3 | PYSEC-2026-3545 |
| Ubuntu:26.10 | python-aiohttp | no fix listed | UBUNTU-CVE-2026-69244 |
Affected products (as reported)
Weakness: CWE-400, CWE-416, CWE-125 · 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
References
- https://github.com/aio-libs/aiohttp/security/advisories/GHSA-cq5v-8q36-5273 x_refsource_CONFIRM
- https://github.com/aio-libs/aiohttp/pull/13223 x_refsource_MISC
- https://github.com/aio-libs/aiohttp/commit/49f65d54150397892f7bcc4aae887767d51c322d x_refsource_MISC
- https://github.com/aio-libs/aiohttp/releases/tag/v3.14.3 x_refsource_MISC