CVE-2025-24970 is a high-severity (CVSS 7.5) Improper Input Validation vulnerability in io.netty:netty-handler. A fix is available for io.netty:netty-handler — see the affected versions and patch details below.
SslHandler doesn't correctly validate packets which can lead to native crash when using native SSLEngine
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
- CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
Exploitation and automatability from CISA’s SSVC triage for CVE-2025-24970.
EPSS Exploitation Probability
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.
How urgent is this, really
CVE-2025-24970 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 378,567 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
io.netty:netty-handlerReal-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
Impact
When a special crafted packet is received via SslHandler it doesn't correctly handle validation of such a packet in all cases which can lead to a native crash.
Workarounds
As workaround its possible to either disable the usage of the native SSLEngine or changing the code from:
SslContext context = ...;
SslHandler handler = context.newHandler(....);
to:
SslContext context = ...;
SSLEngine engine = context.newEngine(....);
SslHandler handler = new SslHandler(engine, ....);
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.netty:netty-handler | ≥ 4.1.91.Final&&< 4.1.118.Final | 4.1.118.Finalio.netty:netty-handler:4.1.118.Final |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-handler, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.netty:netty-handler to 4.1.118.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-24970 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-2025-24970 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-24970. 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.
This vulnerability in Netty's SslHandler is of important severity rather than moderate because it directly impacts the stability and reliability of applications using native SSLEngine. By sending a specially crafted packet, an attacker can trigger a native crash, leading to a complete process termination. Unlike…
| Product | Fixed in | Advisory |
|---|---|---|
| HawtIO HawtIO 4.2.0 | netty-handler | RHSA-2025:8761 |
| Red Hat build of Apache Camel 4.8.5 for Spring Boot | netty-handler | RHSA-2025:3543 |
| Red Hat Build of Apache Camel 4.8 for Quarkus 3.15 | netty-handler | RHSA-2025:2067 |
| Red Hat build of Quarkus 3.15.3.SP1 | netty-handler | RHSA-2025:1885 |
| Red Hat build of Quarkus 3.20.1 | netty-handler | RHSA-2025:8258 |
| Red Hat build of Quarkus 3.8.6.SP3 | netty-handler | RHSA-2025:1884 |
| Red Hat Data Grid | netty-handler | RHSA-2025:2663 |
| Red Hat JBoss Enterprise Application Platform | io.netty/netty-handler:4.1.124.Final-redhat-00001 | RHSA-2025:3467 |
Frequently Asked Questions
Is CVE-2025-24970 in your dependencies?
O3 Security finds CVE-2025-24970 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.