How severe is CVE-2024-8391?

No CVSS score has been assigned to CVE-2024-8391 yet. Review the advisory details and affected package list to assess your exposure.

Which packages are affected by CVE-2024-8391?

CVE-2024-8391 affects the following packages: io.vertx:vertx-grpc-server (Maven), io.vertx:vertx-grpc-client (Maven). Ecosystems affected: Maven.

How do I fix CVE-2024-8391?

Update io.vertx:vertx-grpc-server to 4.5.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-8391 is resolved across your whole dependency graph.

How do I detect CVE-2024-8391 in my Maven dependencies?

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

How do I mitigate CVE-2024-8391 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-2024-8391?

O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-8391 can be triaged on real exposure rather than presence alone.

Is CVE-2024-8391 actively exploited in the wild?

No public exploit code has been indexed for CVE-2024-8391 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 CVE-2024-8391?

CVE-2024-8391 has an EPSS (Exploit Prediction Scoring System) score of 0.6%, placing it in the 46th 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 CVE-2024-8391?

CVE-2024-8391 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 CVE-2024-8391 published, and has it been updated?

CVE-2024-8391 was published on September 4, 2024 and was last updated on August 12, 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

Not in CISA KEV

CVE-2024-8391 — vertx-grpc-server

Fix: eclipse-vertx/vertx-grpc@a76b14a

CVE-2024-8391 is a CWE-770 vulnerability in io.vertx:vertx-grpc-server. A fix is available for io.vertx:vertx-grpc-server — see the affected versions and patch details below.

Eclipse Vert.x gRPC server does not limit the maximum message size

Also known asGHSA-g76f-gjfx-4rpr

Published

Sep 4, 2024

Updated

Aug 12, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Sep 21, 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 CVE-2024-8391.

EPSS Exploitation Probability

via FIRST.org ↗

0.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs46th percentile — riskier than 46% 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

2 pkgs affected

☕io.vertx:vertx-grpc-server☕io.vertx:vertx-grpc-client

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

In Eclipse Vert.x version 4.3.0 to 4.5.9, the gRPC server does not limit the maximum length of message payload (Maven GAV: io.vertx:vertx-grpc-server and io.vertx:vertx-grpc-client).

This is fixed in the 4.5.10 version.

Note this does not affect the Vert.x gRPC server based grpc-java and Netty libraries (Maven GAV: io.vertx:vertx-grpc)

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`io.vertx:vertx-grpc-server`	≥ 4.3.0&&< 4.5.10	4.5.10`io.vertx:vertx-grpc-server:4.5.10`
☕Maven	`io.vertx:vertx-grpc-client`	≥ 4.3.0&&< 4.5.10	4.5.10`io.vertx:vertx-grpc-client:4.5.10`

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.vertx:vertx-grpc-server, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.vertx:vertx-grpc-server to 4.5.10 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-8391 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2024-8391 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2024-8391. 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

Product	Fixed in	Advisory
Red Hat build of Apache Camel 4 for Quarkus 3	`vertx-grpc-client`	RHSA-2024:7052
Red Hat build of Quarkus 3.8.6.redhat	`io.vertx/vertx-grpc-client:4.5.7.redhat-00003`	RHSA-2024:6437
Red Hat JBoss EAP XP 5.0 Update 1.0	`vertx-grpc`	RHSA-2025:0542
RHOSS-1.34-RHEL-8	`openshift-serverless-1/logic-data-index-ephemeral-rhel8:1.34.0-6`	RHSA-2024:8023

Frequently Asked Questions

In Eclipse Vert.x version 4.3.0 to 4.5.9, the gRPC server does not limit the maximum length of message payload (Maven GAV: io.vertx:vertx-grpc-server and io.vertx:vertx-grpc-client). This is fixed in the 4.5.10 version. Note this does not affect the Vert.x gRPC server based grpc-java and Netty libraries (Maven GAV: io.vertx:vertx-grpc)

O3 Security · Impact-Aware SCA

Is CVE-2024-8391 in your dependencies?

O3 Security finds CVE-2024-8391 across Maven 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