Requests HTTP Basic Auth credentials extracted from URL are

The Fix

pip install requests==2.27.0

Based on closed psf/requests issue #1767 · 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

@@ -21,8 +21,8 @@
 from . import certs
 from .compat import parse_http_list as _parse_list_header
-from .compat import (quote, urlparse, bytes, str, OrderedDict, urlunparse,
-                     is_py2, is_py3, builtin_str, getproxies, proxy_bypass)
+from .compat import (quote, urlparse, bytes, str, OrderedDict, unquote, is_py2,

fix.md

Option A — Upgrade to fixed release\npip install requests==2.27.0\nWhen NOT to use: This fix should not be applied if the application relies on the original encoding behavior.\n\n

Why This Fix Works in Production

Trigger: Users received '401 Unauthorized' errors due to spaces in passwords being replaced with '%20'.
Mechanism: HTTP Basic Auth credentials were incorrectly %-encoded when extracted from URLs
Why the fix works: Fixes the issue of HTTP Basic Auth credentials being %-encoded when extracted from URLs by unquoting the URL before parsing it. (first fixed release: 2.27.0).

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

HTTP Basic Auth credentials were incorrectly %-encoded when extracted from URLs
Production symptom (often without a traceback): Users received '401 Unauthorized' errors due to spaces in passwords being replaced with '%20'.

Proof / Evidence

GitHub issue: #1767
Fix PR: https://github.com/psf/requests/pull/1768
First fixed release: 2.27.0
Reproduced locally: No (not executed)
Last verified: 2026-02-07
Confidence: 0.95
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.72

Discussion

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

Jump to Sources Open on GitHub

“Hmm, that behaviour feels wrong to me. Probably should fix this. =) Thanks! :cake:”

@Lukasa · 2013-12-01 · source

Failure Signature (Search String)

Users received '401 Unauthorized' errors due to spaces in passwords being replaced with '%20'.

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Users received '401 Unauthorized' errors due to spaces in passwords being replaced with '%20'.

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Users received '401 Unauthorized' errors due to spaces in passwords being replaced with '%20'.

What Broke

Users received '401 Unauthorized' errors due to spaces in passwords being replaced with '%20'.

Why It Broke

HTTP Basic Auth credentials were incorrectly %-encoded when extracted from URLs

Fix Options (Details)

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

pip install requests==2.27.0

When NOT to use: This fix should not be applied if the application relies on the original encoding behavior.

Use when you can deploy the upstream fix. It is usually lower-risk than long-lived workarounds.

Fix reference: https://github.com/psf/requests/pull/1768

First fixed release: 2.27.0

Last verified: 2026-02-07. Validate in your environment.

When NOT to Use This Fix

This fix should not be applied if the application relies on the original encoding behavior.

Did This Fix Work in Your Case?

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

Prevention

Capture the exact failing error string in logs and tests so you can reproduce via a minimal script.
Pin production dependencies and upgrade only with a reproducible test that hits the failing path.

Version Compatibility Table

Version	Status
2.27.0	Fixed

Related Issues

No related fixes found.

Cluster: requests:configuration-error Requests hub Requests 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.

Requests HTTP Basic Auth credentials extracted from URL are %-encoded (Fix)