How severe is GHSA-hf5h-hh56-3vrg?

No CVSS score has been assigned to GHSA-hf5h-hh56-3vrg yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by GHSA-hf5h-hh56-3vrg?

GHSA-hf5h-hh56-3vrg affects the following packages: uws (npm). Ecosystems affected: npm.

How do I fix GHSA-hf5h-hh56-3vrg?

Update uws to 0.10.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hf5h-hh56-3vrg is resolved across your whole dependency graph.

How do I detect GHSA-hf5h-hh56-3vrg in my npm dependencies?

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

How do I mitigate GHSA-hf5h-hh56-3vrg 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.

Is GHSA-hf5h-hh56-3vrg actively exploited in the wild?

No public exploit code has been indexed for GHSA-hf5h-hh56-3vrg 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-hf5h-hh56-3vrg?

GHSA-hf5h-hh56-3vrg has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 70th 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-hf5h-hh56-3vrg?

GHSA-hf5h-hh56-3vrg is classified as Uncontrolled Resource Consumption (CWE-400), Improper Input Validation (CWE-20). These weakness types describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was GHSA-hf5h-hh56-3vrg published, and has it been updated?

GHSA-hf5h-hh56-3vrg was published on September 1, 2020 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

📦 npm

Not in CISA KEV

Denial of Service in uwsGHSA-hf5h-hh56-3vrg

Fix: uWebSockets/uWebSockets@37deefd

GHSA-hf5h-hh56-3vrg is a Uncontrolled Resource Consumption vulnerability in uws. A fix is available for uws — see the affected versions and patch details below.

Also known asCVE-2016-10544

Published

Sep 1, 2020

Updated

Nov 8, 2023

Affected

1 pkg

Patched

1 / 1

Exploits

None indexed

Exploitation data as of Oct 12, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk-0.02%

Lower risk than most CVEs70th percentile — riskier than 70% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

Real-World Exposure

1 pkg affected

How broadly this vulnerability is actually deployed: weekly install volume shows current usage, and reverse-dependency count shows how many other packages break if it stays unpatched.

227other npm packages depend on this — each one inherits the vulnerability until it's patched upstream

uwsnpm

86Kdownloads / week

Description

Affected versions of uws do not properly handle large websocket messages when permessage-deflate is enabled, which may result in a denial of service condition.

If uws recieves a 256Mb websocket message when permessage-deflate is enabled, the server will compress the message prior to executing the length check, and subsequently extract the message prior to processing. This can result in a situation where an excessively large websocket message passes the length checks, yet still gets cast from a Buffer to a string, which will exceed v8's maximum string size and crash the process.

Recommendation

Update to version 0.10.9 or later.

Alternatively, disable permessage-deflate.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
📦npm	`uws`	≥ 0.10.0&&< 0.10.9	0.10.9`npm install uws@0.10.9`

Affected Products

1 product · 1 configurations

Application

uwsuws_project

≥ 0.10.0 && ≤ 0.10.8

range

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for uws, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update uws to 0.10.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-hf5h-hh56-3vrg 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.

Frequently Asked Questions

Affected versions of `uws` do not properly handle large websocket messages when `permessage-deflate` is enabled, which may result in a denial of service condition. If `uws` recieves a 256Mb websocket message when `permessage-deflate` is enabled, the server will compress the message prior to executing the length check, and subsequently extract the message prior to processing. This can result in a situation where an excessively large websocket message passes the length checks, yet still gets cast from a Buffer to a string, which will exceed v8's maximum string size and crash the process. ## R

O3 Security · Impact-Aware SCA

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