CVE-2026-39852 — quarkus-vertx-http
HIGHCVE-2026-39852 is a high-severity (CVSS 8.2) CWE-863 vulnerability in io.quarkus:quarkus-vertx-http. A fix is available for io.quarkus:quarkus-vertx-http — see the affected versions and patch details below.
Quarkus has Authentication/Authorization bypasses
Exploitation Status
No confirmed exploitation observed yet
- 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-2026-39852.
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-2026-39852 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 377,238 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-http☕io.quarkus:quarkus-vertx-http☕io.quarkus:quarkus-vertx-http☕io.quarkus:quarkus-vertx-httpReal-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
Quarkus version 3.32.4 is vulnerable to an authorization bypass issue (GHSL-2026-099), in which semicolons (matrix parameters) in HTTP requests can be used to bypass security constraints, potentially allowing unauthorized access to protected resources.
Unauthenticated or lower-privileged users can bypass HTTP path-based authorization policies by appending a semicolon (;) and arbitrary text to the request URL. The vulnerability arises from a path-normalization inconsistency: Quarkus's security layer performs authorization checks on the raw URL path (which preserves matrix parameters), whereas RESTEasy Reactive's routing layer strips matrix parameters before matching endpoints. This allows requests like /api/admin;anything to bypass policies protecting /api/admin while still routing to the protected endpoint.
Impact
This issue may lead to Authentication/Authorization bypasses.
Credits
This issue was discovered with the GitHub Security Lab Taskflow Agent and manually verified by GHSL team members @p- (Peter Stöckli) and @m-y-mo (Man Yue Mo).
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.quarkus:quarkus-vertx-http | all versions | 3.20.6.1io.quarkus:quarkus-vertx-http:3.20.6.1 |
| ☕Maven | io.quarkus:quarkus-vertx-http | ≥ 3.21.0&&< 3.27.3.1 | 3.27.3.1io.quarkus:quarkus-vertx-http:3.27.3.1 |
| ☕Maven | io.quarkus:quarkus-vertx-http | ≥ 3.30.0&&< 3.33.1.1 | 3.33.1.1io.quarkus:quarkus-vertx-http:3.33.1.1 |
| ☕Maven | io.quarkus:quarkus-vertx-http | ≥ 3.34.0&&< 3.35.1.1 | 3.35.1.1io.quarkus:quarkus-vertx-http:3.35.1.1 |
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-http, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.quarkus:quarkus-vertx-http to 3.20.6.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2026-39852 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-2026-39852 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2026-39852. 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 |
|---|---|---|
| Cryostat 4 on RHEL 9 | cryostat/cryostat-reports-rhel9:4.2.0-9 | RHSA-2026:17789 |
| HawtIO HawtIO 4.4.0 | quarkus-vertx-http | RHSA-2026:25089 |
| Red Hat Build of Apache Camel 4.14 for Quarkus 3.27 | quarkus-vertx-http | RHSA-2026:13631 |
| Red Hat build of Quarkus 3.20.6.SP1 | quarkus-vertx-http | RHSA-2026:11720 |
| Red Hat build of Quarkus 3.27.3.SP1 | see advisory | RHSA-2026:11721 |
| Streams for Apache Kafka 2.9.4 | quarkus-vertx-http | RHSA-2026:34608 |
| Streams for Apache Kafka 3.2.1 | quarkus-vertx-http | RHSA-2026:54435 |
Frequently Asked Questions
Is CVE-2026-39852 in your dependencies?
O3 Security finds CVE-2026-39852 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.