CVE-2025-49574 is a medium-severity (CVSS 6.4) CWE-668 vulnerability in io.quarkus:quarkus-vertx. A fix is available for io.quarkus:quarkus-vertx — see the affected versions and patch details below.
Quarkus potential data leak when duplicating a duplicated context
Exploitation Status
No confirmed exploitation observed yet
- A successful exploit gives an attacker total control of the affected component, not partial access.
- 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-2025-49574.
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-2025-49574 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.quarkus:quarkus-vertx☕io.quarkus:quarkus-vertx☕io.quarkus:quarkus-vertxReal-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
Vert.x 4.5.12 has changed the semantics of the duplication of duplicated context.
Duplicated context is an object used to propagate data through a processing (synchronous or asynchronous). Each "transaction" or "processing" runs on its own isolated duplicated context.
Initially, duplicating a duplicated context was creating a fresh (empty) new context, meaning that the new duplicated context can be used to managed a separated transaction.
In Vert.x 4.5.12, this semantics has changed, and since the content of the parent duplicated context is copied into the new one, potentially leaking data.
This CVE is especially for Quarkus as Quarkus extensively uses the Vert.x duplicated context to implement context propagation. With the new semantic data from one transaction can leak to the data from another transaction. From a Vert.x point of view, this new semantic clarifies the behavior.
A significant amount of data is stored in the duplicated context, including request scope, security details, and metadata. Duplicating a duplicated context is rather rare and is only done in a few places:
- Quarkus REST Client when using OTel (but it's the same transaction, so no leak)
- Quarkus Messaging connectors
- Quarkus SmallRye Health (same transaction, so no leak)
Patches
After discussion with the Vert.x team, the change will be rolled back in Vert.x 4.x. A new API will be added to Vert.x 5 do distinguish the 2 cases.
Workarounds
When duplicating a duplicated context, the following code can be done to avoid the potential leak:
((ContextInternal) VertxContext.getRootContext(ctx)).duplicate()
This workaround would not be required once the Vert.x version containing the fix will be included. Note that the workaround would still work.
References
This issue have been reported in https://github.com/quarkusio/quarkus/issues/48227.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.quarkus:quarkus-vertx | all versions | 3.15.6io.quarkus:quarkus-vertx:3.15.6 |
| ☕Maven | io.quarkus:quarkus-vertx | ≥ 3.16.0.CR1&&< 3.20.2 | 3.20.2io.quarkus:quarkus-vertx:3.20.2 |
| ☕Maven | io.quarkus:quarkus-vertx | ≥ 3.21.0.CR1&&< 3.24.1 | 3.24.1io.quarkus:quarkus-vertx:3.24.1 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.quarkus:quarkus-vertx, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.quarkus:quarkus-vertx to 3.15.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-49574 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-2025-49574 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-49574. 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.
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat build of Quarkus 3.15.6 | quarkus-bom | RHSA-2025:13012 |
| Red Hat build of Quarkus 3.20.2 | quarkus-bom | RHSA-2025:13010 |
| Streams for Apache Kafka 3.0.0 | see advisory | RHSA-2025:12511 |
| Streams for Apache Kafka 3.1.0 | quarkus-vertx | RHSA-2025:23417 |
Frequently Asked Questions
Is CVE-2025-49574 in your dependencies?
O3 Security finds CVE-2025-49574 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.