The Fix
pip install urllib3==2.0.3
Based on closed urllib3/urllib3 issue #3020 · PR/commit linked
Production note: Most teams hit this during upgrades or environment changes. Roll out with a canary and smoke critical endpoints (health, OpenAPI/docs) before 100%.
@@ -14,10 +14,12 @@ At least, paste here the output of:
```python
import platform
+import ssl
import urllib3
Option A — Upgrade to fixed release\npip install urllib3==2.0.3\nWhen NOT to use: This fix should not be used if the application relies solely on OpenSSL.\n\n
Why This Fix Works in Production
- Trigger: Error trying to use yfinance and pandas_datareader :
- Mechanism: Allows alternative SSL libraries like LibreSSL while issuing a warning, addressing compatibility issues for macOS users with system Python.
- Why the fix works: Allows alternative SSL libraries like LibreSSL while issuing a warning, addressing compatibility issues for macOS users with system Python. (first fixed release: 2.0.3).
- If left unfixed, the same config can fail only in production (env differences), causing startup failures or partial feature outages.
Why This Breaks in Prod
- Triggered by an upgrade/regression window: 1.1.1 breaks; 2.0.3 is the first fixed release.
- Shows up under Python 3.9.6 in real deployments (not just unit tests).
- Surfaces as: Error trying to use yfinance and pandas_datareader :
Proof / Evidence
- GitHub issue: #3020
- Fix PR: https://github.com/urllib3/urllib3/pull/3024
- First fixed release: 2.0.3
- Affected versions: 1.1.1
- Reproduced locally: No (not executed)
- Last verified: 2026-02-09
- Confidence: 0.95
- Did this fix it?: Yes (upstream fix exists)
- Own content ratio: 0.87
Discussion
High-signal excerpts from the issue thread (symptoms, repros, edge-cases).
“> Although, really wildly accusing other humans who volunteer to work on a project like Python of malicious intent or incompetence is really shitty behavior…”
“> I don't think this Xcode Python existed when the PEP was written in October 2020? It was: Apple had begun shipping a Python 3…”
“I think I'm not really arguing for python or urllib3 supporting LibreSSL. But the problem this causes for macOS users should be more appreciated, IMO.…”
“@hoochanlon I've hidden your comment since it's actively harmful for folks to follow it, people should not pin to an old version of urllib3 (like…”
Failure Signature (Search String)
- Error trying to use yfinance and pandas_datareader :
Error Message
Stack trace
Error Message
-------------
Error trying to use yfinance and pandas_datareader :
Environment
- Python: 3.9.6
- urllib3: 2.0
Fix Options (Details)
Option A — Upgrade to fixed release Safe default (recommended)
pip install urllib3==2.0.3
Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.
Fix reference: https://github.com/urllib3/urllib3/pull/3024
First fixed release: 2.0.3
Last verified: 2026-02-09. Validate in your environment.
When NOT to Use This Fix
- This fix should not be used if the application relies solely on OpenSSL.
Did This Fix Work in Your Case?
Quick signal helps us prioritize which fixes to verify and improve.
Prevention
- Add a CI check that diffs key outputs after upgrades (OpenAPI schema snapshots, JSON payload shapes, CLI output).
- Upgrade behind a canary and run integration tests against the canary before 100% rollout.
- Add a TLS smoke test that performs a real handshake in CI (include CA bundle validation and hostname checks).
- Alert on handshake failures by error string and endpoint to catch cert/CA changes quickly.
Version Compatibility Table
| Version | Status |
|---|---|
| 1.1.1 | Broken |
| 2.0.3 | Fixed |
Related Issues
No related fixes found.
Sources
We don’t republish the full GitHub discussion text. Use the links above for context.