CVE-2025-50182 is a medium-severity (CVSS 5.3) Open Redirect vulnerability in urllib3. A fix is available for urllib3 — see the affected versions and patch details below.
urllib3 does not control redirects in browsers and Node.js
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-2025-50182.
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-2025-50182 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
urllib3Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects PyPI packages — download data is not available via public APIs for these ecosystems.
Description
urllib3 supports being used in a Pyodide runtime utilizing the JavaScript Fetch API or falling back on XMLHttpRequest. This means you can use Python libraries to make HTTP requests from your browser or Node.js. Additionally, urllib3 provides a mechanism to control redirects.
However, the retries and redirect parameters are ignored with Pyodide; the runtime itself determines redirect behavior.
Affected usages
Any code which relies on urllib3 to control the number of redirects for an HTTP request in a Pyodide runtime.
Impact
Redirects are often used to exploit SSRF vulnerabilities. An application attempting to mitigate SSRF or open redirect vulnerabilities by disabling redirects may remain vulnerable if a Pyodide runtime redirect mechanism is unsuitable.
Remediation
If you use urllib3 in Node.js, upgrade to a patched version of urllib3.
Unfortunately, browsers provide no suitable way which urllib3 can use: XMLHttpRequest provides no control over redirects, the Fetch API returns opaqueredirect responses lacking data when redirects are controlled manually. Expect default browser behavior for redirects.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐍PyPI | urllib3 | ≥ 2.2.0&&< 2.5.0 | 2.5.0pip install --upgrade 'urllib3==2.5.0' |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for urllib3, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update urllib3 to 2.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-50182 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-2025-50182 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2025-50182. 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.
The vulnerability lies in the urllib3 library's inability to control HTTP redirects when executed within a Pyodide runtime. This can lead to Server-Side Request Forgery (SSRF) attacks, where an attacker can induce the application to make requests to unintended internal or external resources. While urllib3 is a…
| Product | Fixed in | Advisory |
|---|---|---|
| Red Hat Ceph Storage 8.1 | rhceph/grafana-rhel9:1787305054 | RHSA-2026:62115 |
| Red Hat Ceph Storage 9 | rhceph/grafana-rhel10:1771399331 | RHSA-2026:3406 |
Frequently Asked Questions
Is CVE-2025-50182 in your dependencies?
O3 Security finds CVE-2025-50182 across PyPI dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.