uvicorn SSL handling (Fix)

The Fix

Added SSL support by creating an SSL context in the worker, allowing secure connections.

Based on closed Kludex/uvicorn issue #8 · 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%.

Open PR/Commit

@@ -1,6 +1,7 @@
 import functools
 import signal
+import ssl
 import sys

fix.md

Option A — Apply the official fix\nAdded SSL support by creating an SSL context in the worker, allowing secure connections.\nWhen NOT to use: Do not use this fix if SSL is not required for your application.\n\n

Why This Fix Works in Production

Trigger: SSL handling
Mechanism: SSL context was not set up in the worker, preventing secure connections

Production impact:

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

SSL context was not set up in the worker, preventing secure connections
Production symptom (often without a traceback): SSL handling

Proof / Evidence

GitHub issue: #8
Fix PR: https://github.com/kludex/uvicorn/pull/26
Reproduced locally: No (not executed)
Last verified: 2026-02-11
Confidence: 0.70
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.88

Discussion

High-signal excerpts from the issue thread (symptoms, repros, edge-cases).

Jump to Sources Open on GitHub

“Set up ssl context in the worker”

Issue thread · issue description · source

Failure Signature (Search String)

SSL handling
Set up ssl context in the worker

Copy-friendly signature

signature.txt

Failure Signature
-----------------
SSL handling
Set up ssl context in the worker

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
SSL handling
Set up ssl context in the worker

What Broke

Inability to establish secure connections, leading to potential data exposure.

Why It Broke

SSL context was not set up in the worker, preventing secure connections

Fix Options (Details)

Option A — Apply the official fix

Added SSL support by creating an SSL context in the worker, allowing secure connections.

When NOT to use: Do not use this fix if SSL is not required for your application.

Fix reference: https://github.com/kludex/uvicorn/pull/26

Last verified: 2026-02-11. Validate in your environment.

When NOT to Use This Fix

Do not use this fix if SSL is not required for your application.

Did This Fix Work in Your Case?

Quick signal helps us prioritize which fixes to verify and improve.

Prevention

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.

Related Issues

No related fixes found.

Cluster: uvicorn:configuration-error All hubs All clusters

Related clusters: Data consistency Race condition SSL handshake

Sources

We don’t republish the full GitHub discussion text. Use the links above for context.