# AIOHTTP: Out-of-bounds heap read in C HTTP response parser error path (malformed chunked response) Advisory record · `GHSA-cq5v-8q36-5273` - **Identifiers:** `GHSA-cq5v-8q36-5273` · `CVE-2026-69244` · `PYSEC-2026-3545` - **State:** Confirmed - **Severity:** CVSS 7.1 High - **Critical:** No - **Weakness (CWE):** [CWE-125](https://cwe.mitre.org/data/definitions/125.html) · [CWE-400](https://cwe.mitre.org/data/definitions/400.html) · [CWE-416](https://cwe.mitre.org/data/definitions/416.html) - **Tags:** [Memory corruption](https://agentprime.io/advisories/tag/memory-corruption.md) · [Denial of service](https://agentprime.io/advisories/tag/dos.md) - **Published:** 3 Aug 2026 - **Updated:** 10 Sept 2026 - **Reviewed by a person:** No Published by the GitHub Advisory Database at 3 Aug 2026, 20:51 UTC. agentprime has not analysed this yet, so whether it affects any app is not known. ## Affected packages - `aiohttp` (PyPI): affected `<3.14.3`; fixed in `3.14.3` ## Machine-written summary Summary written by Claude Haiku from the source advisory. Not reviewed by a person. > The aiohttp package, versions before 3.14.3, is vulnerable to an out-of-bounds heap read in its C HTTP response parser while it builds an error message for a malformed response. An attacker-controlled server, or possibly an accidental malformed response, could cause a denial of service in the client. Upgrade to aiohttp 3.14.3 or later. If you cannot upgrade, set the environment variable AIOHTTP_NO_EXTENSIONS=1 to use the Python parser, which the source says is unaffected. Written 1 Nov 2026. ## Not analysed yet We haven’t published our analysis of this Advisory yet. Once a person has reviewed it, this page will say what’s vulnerable, what has to be true for your app to be affected, and how to check. ## Severity and exploitation - 7.1 High, CVSS 4.0: `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`, from CNA (GitHub_M) - **CISA KEV:** Not listed. - **EPSS:** 0.0053, the 45th percentile, on 14 Nov 2026: FIRST’s estimate of the chance of exploitation in the next 30 days. ## Timeline - 25 Jul 2026, 12:18 UTC: [Published by the maintainers as a GitHub repository advisory](https://github.com/aio-libs/aiohttp/security/advisories/GHSA-cq5v-8q36-5273) - 31 Oct 2026, 14:10 UTC: First seen by agentprime - 31 Oct 2026, 14:10 UTC: [Confirmed by OSV](https://osv.dev/vulnerability/GHSA-cq5v-8q36-5273) ## Sources - [GitHub Advisory Database: GHSA-cq5v-8q36-5273](https://github.com/advisories/GHSA-cq5v-8q36-5273) - [OSV: GHSA-cq5v-8q36-5273](https://osv.dev/vulnerability/GHSA-cq5v-8q36-5273) - - - - - Facts on this page come from the GitHub Advisory Database (CC-BY 4.0), OSV and the other sources listed, as published. We don’t reproduce full advisory descriptions, which can contain exploit code. ## Check whether this affects you A Match means an installed version is in the affected range above. Most don’t affect the app; agentprime hasn’t analysed this one yet. - With the agentprime MCP server (), ask your agent to check the project: `check_lockfile` sends a lockfile, `check_packages` a list of installed packages, and both return the Matches and the upgrades that clear them. `get_advisory` returns this record. Setup: - In a browser: reads your lockfile in the browser, never uploading it. - Whether it touches your code, with file and line: the Claude Code plugin, - As JSON: , or `POST https://api.agentprime.io/v1/match` with your packages () --- The web page: . Everything for agents: .