How severe is GHSA-4fvr-rgm6-gqmc?

No CVSS score has been assigned to GHSA-4fvr-rgm6-gqmc yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-4fvr-rgm6-gqmc?

GHSA-4fvr-rgm6-gqmc affects the following packages: aiohttp (PyPI). Ecosystems affected: PyPI.

How do I fix GHSA-4fvr-rgm6-gqmc?

Update aiohttp to 3.14.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4fvr-rgm6-gqmc is resolved across your whole dependency graph.

How do I detect GHSA-4fvr-rgm6-gqmc in my PyPI dependencies?

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.

How do I mitigate GHSA-4fvr-rgm6-gqmc if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

How does O3 Security protect against GHSA-4fvr-rgm6-gqmc?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-4fvr-rgm6-gqmc can be triaged on real exposure rather than presence alone.

Is GHSA-4fvr-rgm6-gqmc actively exploited in the wild?

No public exploit code has been indexed for GHSA-4fvr-rgm6-gqmc yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for GHSA-4fvr-rgm6-gqmc?

GHSA-4fvr-rgm6-gqmc has an EPSS (Exploit Prediction Scoring System) score of 0.5%, placing it in the 40th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is GHSA-4fvr-rgm6-gqmc?

GHSA-4fvr-rgm6-gqmc is classified as CWE-770 (CWE-770). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-4fvr-rgm6-gqmc published, and has it been updated?

GHSA-4fvr-rgm6-gqmc was published on June 15, 2026 and was last updated on September 10, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🐍 PyPI

Not in CISA KEV

GHSA-4fvr-rgm6-gqmc — aiohttp

Fix: aio-libs/aiohttp@dfdfa9d

GHSA-4fvr-rgm6-gqmc is a CWE-770 vulnerability in aiohttp. A fix is available for aiohttp — see the affected versions and patch details below.

aiohttp: HTTP/1 Pipelined Requests Queue Without Limit

Also known asCVE-2026-54273PYSEC-2026-2107

Published

Jun 15, 2026

Updated

Sep 10, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Sep 26, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
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-4fvr-rgm6-gqmc.

EPSS Exploitation Probability

via FIRST.org ↗

0.5%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs40th percentile — riskier than 40% 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

AIOHTTP is an asynchronous HTTP client/server framework for asyncio and Python. Prior to 3.14.1, no limit was present on the number of pipelined requests that could be queued. An attacker may be able to use pipelined requests to use excessive amounts of memory, potentially leading to DoS. This vulnerability is fixed in 3.14.1.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🐍PyPI	`aiohttp`	all versions	3.14.1`pip install --upgrade 'aiohttp==3.14.1'`

Detection & mitigation playbook

Open-source dependency

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.
Fix
Update aiohttp to 3.14.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-4fvr-rgm6-gqmc is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like GHSA-4fvr-rgm6-gqmc can be triaged on real exposure rather than presence alone.

Tailored to GHSA-4fvr-rgm6-gqmc. 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 HatModerate

This vulnerability is rated Moderate because an unauthenticated remote attacker can trigger denial of service against an affected aiohttp HTTP/1 server by sending a large number of pipelined requests, causing excessive memory consumption. Exploitation requires aiohttp to be deployed as an HTTP/1 server that accepts…

Workaround published by Red Hat

Update the aiohttp package to version 3.14.1 or later. Until updated builds are available for a given product, reduce exposure by not exposing aiohttp-based HTTP/1 servers directly to untrusted networks. A reverse proxy in front of the service can help limit abusive pipelined request patterns. Installations that use aiohttp only as an HTTP client, or that do not accept HTTP/1 pipelined requests on an aiohttp server, are not affected by this flaw.

Source: Red Hat security advisory for GHSA-4fvr-rgm6-gqmc (CC BY 4.0)

Frequently Asked Questions

### Summary No limit was present on the number of pipelined requests that could be queued. ### Impact An attacker may be able to use pipelined requests to use excessive amounts of memory, potentially leading to DoS. ----- Patch: https://github.com/aio-libs/aiohttp/commit/dfdfa9d5aad5d21f91c79fb2ceeba0f8046cb6cf

O3 Security · Impact-Aware SCA

Is GHSA-4fvr-rgm6-gqmc in your dependencies?

O3 Security finds GHSA-4fvr-rgm6-gqmc across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

Scan my dependencies How O3 SCA works