GHSA-m5qp-6w8w-w647 is a high-severity (CVSS 7.5) CWE-770 vulnerability in aiohttp. O3 Security confirms whether GHSA-m5qp-6w8w-w647 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
AIOHTTP has a Multipart Header Size Bypass
Real-World Exposure
aiohttpReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
Summary
A response with an excessive number of multipart headers may be allowed to use more memory than intended, potentially allowing a DoS vulnerability.
Impact
Multipart headers were not subject to the same size restrictions in place for normal headers, potentially allowing substantially more data to be loaded into memory than intended. However, other restrictions in place limit the impact of this vulnerability.
Patch: https://github.com/aio-libs/aiohttp/commit/8a74257b3804c9aac0bf644af93070f68f6c5a6f
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | aiohttp | all versions | 3.13.4 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aiohttp. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update aiohttp to 3.13.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-m5qp-6w8w-w647 is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-m5qp-6w8w-w647 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-m5qp-6w8w-w647. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-m5qp-6w8w-w647 in your dependencies?
O3 detects GHSA-m5qp-6w8w-w647 across PyPI dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.