CVE-2025-22227 is a medium-severity (CVSS 6.1) Information Exposure vulnerability in io.projectreactor.netty:reactor-netty-http. A fix is available for io.projectreactor.netty:reactor-netty-http — see the affected versions and patch details below.
Reactor Netty HTTP is vulnerable to credential leaks during chained redirects
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-2025-22227.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
io.projectreactor.netty:reactor-netty-http☕io.projectreactor.netty:reactor-netty-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
In some specific scenarios with chained redirects, Reactor Netty HTTP client leaks credentials. In order for this to happen, the HTTP client must have been explicitly configured to follow redirects.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | io.projectreactor.netty:reactor-netty-http | ≥ 1.3.0-M1&&< 1.3.0-M5 | 1.3.0-M5io.projectreactor.netty:reactor-netty-http:1.3.0-M5 |
| ☕Maven | io.projectreactor.netty:reactor-netty-http | all versions | 1.2.8io.projectreactor.netty:reactor-netty-http:1.2.8 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.projectreactor.netty:reactor-netty-http, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.projectreactor.netty:reactor-netty-http to 1.3.0-M5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-22227 is resolved across your whole dependency graph.
Workarounds
Assume what was exposed is already known: rotate any credential, token or key that the affected component could return, restrict the endpoint to callers that genuinely need it, and strip sensitive fields from responses and error output at the boundary rather than relying on the client not to read them.
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 is rated as Moderate because it requires a specific, non-default configuration to be exploitable. While it involves the leakage of credentials, the impact is lessened by the prerequisite that the Reactor Netty HTTP client must be explicitly configured to follow redirects. This requirement reduces…
Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.Source: Red Hat security advisory for CVE-2025-22227 (CC BY 4.0)
Frequently Asked Questions
Is CVE-2025-22227 in your dependencies?
Find it across Maven, including transitive dependencies.