Requests Requests now forcing TLS 1.2 on Python 3.6.10 (Fix)

The Fix

pip install requests==2.27.0

Based on closed psf/requests issue #5555 · 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

@@ -4,9 +4,14 @@ Release History
 ---
 
-**Bugfixes**
+**Improvements**
+

repro.py

{
  "chardet": {
    "version": "3.0.4"
  },
  "cryptography": {
    "version": "2.8"
  },
  "idna": {
    "version": "2.10"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.6.10"
  },
  "platform": {
    "release": "10",
    "system": "Windows"
  },
  "pyOpenSSL": {
    "openssl_version": "1010105f",
    "version": "19.1.0"
  },
  "requests": {
    "version": "2.24.0"
  },
  "system_ssl": {
    "version": "1000214f"
  },
  "urllib3": {
    "version": "1.25.9"
  },
  "using_pyopenssl": true
}

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 requests==2.27.0\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: Requests now forcing TLS 1.2 on Python 3.6.10
Mechanism: Modifies the behavior of pyOpenSSL usage in requests to only activate when SNI is not supported, addressing TLS version issues on Python 3.6.10.
Why the fix works: Modifies the behavior of pyOpenSSL usage in requests to only activate when SNI is not supported, addressing TLS version issues on Python 3.6.10. (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

Shows up under Python 3.6.10 in real deployments (not just unit tests).
Production symptom (often without a traceback): Requests now forcing TLS 1.2 on Python 3.6.10

Proof / Evidence

GitHub issue: #5555
Fix PR: https://github.com/psf/requests/pull/5443
First fixed release: 2.27.0
Reproduced locally: No (not executed)
Last verified: 2026-02-09
Confidence: 0.95
Did this fix it?: Yes (upstream fix exists)
Own content ratio: 0.55

Discussion

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

Jump to Sources Open on GitHub

“Hey @cleebp, Thanks for bringing this up! I don't think we'd taken this into account when pushing pyopenssl to the background”

@nateprewitt · 2020-08-11 · source

“Resolving since we haven't seen any further feedback on this and it's easily resolvable by the end user.”

@nateprewitt · 2020-11-10 · source

Failure Signature (Search String)

Requests now forcing TLS 1.2 on Python 3.6.10
On Python 3.6.10 with `pyopenssl` installed requests should use the highest TLS available, 1.3 (from `pyopenssl`), not 1.2 (from `ssl`).

Copy-friendly signature

signature.txt

Failure Signature
-----------------
Requests now forcing TLS 1.2 on Python 3.6.10
On Python 3.6.10 with `pyopenssl` installed requests should use the highest TLS available, 1.3 (from `pyopenssl`), not 1.2 (from `ssl`).

Error Message

Signature-only (no traceback captured)

error.txt

Error Message
-------------
Requests now forcing TLS 1.2 on Python 3.6.10
On Python 3.6.10 with `pyopenssl` installed requests should use the highest TLS available, 1.3 (from `pyopenssl`), not 1.2 (from `ssl`).

Minimal Reproduction

repro.py

{
  "chardet": {
    "version": "3.0.4"
  },
  "cryptography": {
    "version": "2.8"
  },
  "idna": {
    "version": "2.10"
  },
  "implementation": {
    "name": "CPython",
    "version": "3.6.10"
  },
  "platform": {
    "release": "10",
    "system": "Windows"
  },
  "pyOpenSSL": {
    "openssl_version": "1010105f",
    "version": "19.1.0"
  },
  "requests": {
    "version": "2.24.0"
  },
  "system_ssl": {
    "version": "1000214f"
  },
  "urllib3": {
    "version": "1.25.9"
  },
  "using_pyopenssl": true
}

Environment

Python: 3.6.10

Fix Options (Details)

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

pip install requests==2.27.0

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/psf/requests/pull/5443

First fixed release: 2.27.0

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 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
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.