How severe is CVE-2023-34054?

CVE-2023-34054 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2023-34054?

CVE-2023-34054 affects the following packages: io.projectreactor.netty:reactor-netty-core (Maven), io.projectreactor.netty:reactor-netty-core (Maven). Ecosystems affected: Maven.

How do I fix CVE-2023-34054?

Update io.projectreactor.netty:reactor-netty-core to 1.1.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-34054 is resolved across your whole dependency graph.

How do I detect CVE-2023-34054 in my Maven dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.projectreactor.netty:reactor-netty-core. 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.

How do I mitigate CVE-2023-34054 if there is no patch (or I can't update yet)?

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 does O3 Security protect against CVE-2023-34054?

O3 pinpoints whether CVE-2023-34054 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.

Is CVE-2023-34054 actively exploited in the wild?

No public exploit code has been indexed for CVE-2023-34054 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.

When was CVE-2023-34054 published, and has it been updated?

CVE-2023-34054 was published on November 28, 2023 and was last updated on July 15, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕ Maven

CVE-2023-34054

MEDIUM

CVE-2023-34054 is a medium-severity (CVSS 5.3) vulnerability in io.projectreactor.netty:reactor-netty-core. O3 Security confirms whether CVE-2023-34054 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.

Reactor Netty HTTP Server Metrics DoS Vulnerability

Also known asGHSA-q24v-hpg3-v3jp

Published

Nov 28, 2023

Updated

Jul 15, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Real-World Exposure

2 pkgs affected

☕io.projectreactor.netty:reactor-netty-core☕io.projectreactor.netty:reactor-netty-core

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Specifically, an application is vulnerable if Reactor Netty HTTP Server built-in integration with Micrometer is enabled.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`io.projectreactor.netty:reactor-netty-core`	≥ 1.1.0&&< 1.1.13	1.1.13
☕Maven	`io.projectreactor.netty:reactor-netty-core`	≥ 1.0.0&&< 1.0.39	1.0.39

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.projectreactor.netty:reactor-netty-core. 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 io.projectreactor.netty:reactor-netty-core to 1.1.13 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2023-34054 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 CVE-2023-34054 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 CVE-2023-34054. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Frequently Asked Questions

In Reactor Netty HTTP Server, versions 1.1.x prior to 1.1.13 and versions 1.0.x prior to 1.0.39, it is possible for a user to provide specially crafted HTTP requests that may cause a denial-of-service (DoS) condition. Specifically, an application is vulnerable if Reactor Netty HTTP Server built-in integration with Micrometer is enabled.

O3 Security · Impact-Aware SCA

Is CVE-2023-34054 in your dependencies?

O3 detects CVE-2023-34054 across Maven dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.

Scan my dependencies How O3 SCA works