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Not in CISA KEV

GHSA-9548-qrrj-x5pj aiohttp

Fix: aio-libs/aiohttp@e8d774f

GHSA-9548-qrrj-x5pj is a CWE-444 vulnerability in aiohttp. A fix is available for aiohttp — see the affected versions and patch details below.

AIOHTTP is vulnerable to HTTP Request/Response Smuggling through incorrect parsing of chunked trailer sections

Also known asCVE-2025-53643PYSEC-2026-1104
Published
Jul 14, 2025
Updated
Sep 10, 2026
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for GHSA-9548-qrrj-x5pj.

EPSS Exploitation Probability

via FIRST.org ↗
0.3%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs24th percentile — riskier than 24% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

Real-World Exposure

1 pkg affected
🐍aiohttp

Real-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

The Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request.

Impact

If a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections.


Patch: https://github.com/aio-libs/aiohttp/commit/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🐍PyPIaiohttpall versions3.12.14pip install --upgrade 'aiohttp==3.12.14'

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for aiohttp, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    Update aiohttp to 3.12.14 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-9548-qrrj-x5pj is resolved across your whole dependency graph.

  3. 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.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-9548-qrrj-x5pj can be triaged on real exposure rather than presence alone.

Tailored to GHSA-9548-qrrj-x5pj. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatLow
ProductFixed inAdvisory
Red Hat Ansible Automation Platform 2.5 for RHEL 8automation-controller-0:4.6.25-1.el8apRHSA-2026:1506
Red Hat Ansible Automation Platform 2.6 for RHEL 9automation-controller-0:4.7.8-1.el9apRHSA-2026:1249
Red Hat Satellite 6.18 for RHEL 9python3.12-aiohttp-0:3.13.3-1.el9pcRHSA-2026:2760
Red Hat Ansible Automation Platform 2.6ansible-automation-platform-26/ee-supported-rhel9:1772508458RHSA-2026:3960
Red Hat OpenShift AI 2.22rhoai/odh-feature-server-rhel9:v2.22.3-1763565765RHSA-2025:22759
Red Hat OpenShift AI 2.25rhoai/odh-feature-server-rhel9:v2.25.1-1765354568RHSA-2025:23531
Red Hat OpenShift Service Mesh 3.0openshift-service-mesh/istio-proxyv2-rhel9:1.24.6-1764181669RHSA-2025:22939
Red Hat OpenShift Service Mesh 3.1openshift-service-mesh/istio-proxyv2-rhel9:1.26.6-1764332723RHSA-2025:22944

Frequently Asked Questions

### Summary The Python parser is vulnerable to a request smuggling vulnerability due to not parsing trailer sections of an HTTP request. ### Impact If a pure Python version of aiohttp is installed (i.e. without the usual C extensions) or AIOHTTP_NO_EXTENSIONS is enabled, then an attacker may be able to execute a request smuggling attack to bypass certain firewalls or proxy protections. ---- Patch: https://github.com/aio-libs/aiohttp/commit/e8d774f635dc6d1cd3174d0e38891da5de0e2b6a
O3 Security · Impact-Aware SCA

Is GHSA-9548-qrrj-x5pj in your dependencies?

O3 Security finds GHSA-9548-qrrj-x5pj across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

GHSA-9548-qrrj-x5pj: aiohttp | O3 Security