urllib3 HTTPConnection should return urllib3.HTTPResponse

The Fix

pip install urllib3==1.26.13

Based on closed urllib3/urllib3 issue #2648 · 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%.

Jump to Verify Open PR/Commit

@@ -0,0 +1,3 @@
@@ -0,0 +1,3 @@
+Modified ``urllib3.HTTPConnection.getresponse`` to return an instance of ``urllib3.HTTPResponse`` instead of ``http.client.HTTPResponse``.
+
+Removed ``urllib3.HTTPResponse.from_httplib``.

repro.py

def test_exceptions():

    parser = ParseExceptions()

    parser.process_method(HTTPConnection.getresponse, module=http.client)

    assert parser.visited_nodes == 24489
    print(parser.raw_exceptions)
    print(parser.found_exceptions)

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

fix.md

Option A — Upgrade to fixed release\npip install urllib3==1.26.13\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: - [x] Research and understand which exceptions can be raised at which stage from `HTTPConnection.urlopen` and `HTTPConnection.getresponse` in both urllib3 and…
Mechanism: Refactor internal APIs to use urllib3.HTTPResponse instead of http.client.HTTPResponse.
Why the fix works: Refactor internal APIs to use urllib3.HTTPResponse instead of http.client.HTTPResponse. (first fixed release: 1.26.13).

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

Production symptom (often without a traceback): - [x] Research and understand which exceptions can be raised at which stage from `HTTPConnection.urlopen` and `HTTPConnection.getresponse` in both urllib3 and http.client. This research should be posted into this issue.

Proof / Evidence

GitHub issue: #2648
Fix PR: https://github.com/urllib3/urllib3/pull/2649
First fixed release: 1.26.13
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.85
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.66

Discussion

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

Jump to Sources Open on GitHub

“@shadycuz It sounds like you're on the right path!”

@sethmlarson · 2022-06-21 · source

“@sethmlarson > Research and understand which exceptions can be raised at which stage from HTTPConnection.urlopen and HTTPConnection.getresponse in both urllib3 and http.client”

@shadycuz · 2022-07-30 · source

“I think super is mostly fixed? I can't remember. Still need to fix the bare raise bug. I did publish the first tool Deep-AST that…”

@shadycuz · 2022-10-04 · source

“@sethmlarson I'm too lazy to do the reaserch on the exceptions..”

@shadycuz · 2022-08-02 · source

Failure Signature (Search String)

- [x] Research and understand which exceptions can be raised at which stage from `HTTPConnection.urlopen` and `HTTPConnection.getresponse` in both urllib3 and http.client. This
- [x] Change existing test cases for the new logic.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
- [x] Research and understand which exceptions can be raised at which stage from `HTTPConnection.urlopen` and `HTTPConnection.getresponse` in both urllib3 and http.client. This research should be posted into this issue.
- [x] Change existing test cases for the new logic.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
- [x] Research and understand which exceptions can be raised at which stage from `HTTPConnection.urlopen` and `HTTPConnection.getresponse` in both urllib3 and http.client. This research should be posted into this issue.
- [x] Change existing test cases for the new logic.

Minimal Reproduction

repro.py

def test_exceptions():

    parser = ParseExceptions()

    parser.process_method(HTTPConnection.getresponse, module=http.client)

    assert parser.visited_nodes == 24489
    print(parser.raw_exceptions)
    print(parser.found_exceptions)

What Broke

Applications relying on urllib3 received incompatible response types, causing errors.

Fix Options (Details)

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

pip install urllib3==1.26.13

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/2649

First fixed release: 1.26.13

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.

Verify Fix

verify

Re-run the minimal reproduction on your broken version, then apply the fix and re-run.

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.
Track RSS + object counts after deployments; alert on monotonic growth and GC pressure.
Add a long-running test that repeats the failing call path and asserts stable memory.

Version Compatibility Table

Version	Status
1.26.13	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.

urllib3 HTTPConnection should return urllib3.HTTPResponse instead of http.client.HTTPResponse (Fix)