urllib3 socket.timeout not wrapped properly (Fix)

The Fix

pip install urllib3==1.25

Based on closed urllib3/urllib3 issue #296 · 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

@@ -173,6 +173,32 @@ def socket_handler(listener):
             socket.setdefaulttimeout(default_timeout)
 
+    def test_delayed_body_read_timeout(self):
+        timed_out = Event()
+

fix.md

Option A — Upgrade to fixed release\npip install urllib3==1.25\nWhen NOT to use: Do not use if it changes public behavior or if the failure cannot be reproduced.\n\n

Why This Fix Works in Production

Trigger: socket.timeout not wrapped properly
Mechanism: Catches the socket.timeout exception and raises a ReadTimeoutError with the request URL included in the exception.
Why the fix works: Catches the socket.timeout exception and raises a ReadTimeoutError with the request URL included in the exception. (first fixed release: 1.25).

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

Shows up under Python 2.7 in real deployments (not just unit tests).
Surfaces as: Traceback (most recent call last):\n File "working_on_req.py", line 7, in <module>\n r = requests.get('http://httpbin.org/delay/50', timeout=0.1)\n File…

Proof / Evidence

GitHub issue: #296
Fix PR: https://github.com/urllib3/urllib3/pull/399
First fixed release: 1.25
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.45

Discussion

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

Jump to Sources Open on GitHub

“I've been going through their code. i wrote some code of my own to timeout: This is all i get. I noticed you also have…”

@adaschevici · 2013-12-13 · source

“Can you provide me with the url you were trying to get when you ran into this?”

@adaschevici · 2013-12-13 · source

“It was a local connection; there was nothing running on the port when it happened (so it shouldn't have timed out in the first first…”

@ThiefMaster · 2013-12-13 · source

“@ThiefMaster does this occur when using urllib3 installed form source and requests installed from source?”

@adaschevici · 2013-12-17 · source

Failure Signature (Search String)

socket.timeout not wrapped properly

Error Message

Stack trace

error.txt

Error Message
-------------
Traceback (most recent call last):\n  File "working_on_req.py", line 7, in <module>\n    r = requests.get('http://httpbin.org/delay/50', timeout=0.1)\n  File "/home/hackawaye/virtual_envs/requests_virtual/local/lib/python2.7/site-packages/requests-2.1.0-py2.7.egg/requests/api.py", line 55, in get\n    return request('get', url, **kwargs)\n  File "/home/hackawaye/virtual_envs/requests_virtual/local/lib/python2.7/site-packages/requests-2.1.0-py2.7.egg/requests/api.py", line 44, in request\n    return session.request(method=method, url=url, **kwargs)\n  File "/home/hackawaye/virtual_envs/requests_virtual/local/lib/python2.7/site-packages/requests-2.1.0-py2.7.egg/requests/sessions.py", line 382, in request\n    resp = self.send(prep, **send_kwargs)\n  File "/home/hackawaye/virtual_envs/requests_virtual/local/lib/python2.7/site-packages/requests-2.1.0-py2.7.egg/requests/sessions.py", line 485, in send\n    r = adapter.send(request, **kwargs)\n  File "/home/hackawaye/virtual_envs/requests_virtual/local/lib/python2.7/site-packages/requests-2.1.0-py2.7.egg/requests/adapters.py", line 381, in send\n    raise Timeout(e)

Environment

Python: 2.7

Fix Options (Details)

Option A — Upgrade to fixed release Safe default (recommended)

pip install urllib3==1.25

When NOT to use: Do not use if it changes public behavior or if the failure cannot be reproduced.

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/399

First fixed release: 1.25

Last verified: 2026-02-09. Validate in your environment.

When NOT to Use This Fix

Do not use if it changes public behavior or if the failure cannot be reproduced.

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.
Make timeouts explicit and test them (unit + integration) to avoid silent behavior changes.
Instrument retries (attempt count + reason) and alert on spikes to catch dependency slowdowns.

Version Compatibility Table

Version	Status
1.25	Fixed

Related Issues

No related fixes found.

Cluster: urllib3:configuration-error urllib3 hub urllib3 best practices All hubs All clusters

Related clusters: Data consistency SSL handshake Other

Sources

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