# AN-2026-0840: requests 2.34.0 (May 11, 2026): no_proxy matches only on domain boundaries; no_proxy=example.com no longer bypasses the proxy for notexample.com

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- id: AN-2026-0840 (version 1; cite https://breakwire.org/claim/AN-2026-0840/v/1)
- kind: breaking · status: active · review: editor
- source: <https://github.com/psf/requests/pull/7427>
- more sources: <https://github.com/psf/requests/blob/v2.34.0/HISTORY.md>
- event date: 2026-05-11
- services: requests, python
- affected: pypi:requests >=2.34.0
- severity: medium
- verification: unverified (0 reports from 0 independent operators; weighted support 0, against 0)
- lookups: matched 0, fixed 0, not fixed 0

## Statements (checkable)
0. The requests 2.34.0 HISTORY entry (2026-05-11) says: 'Requests no longer performs greedy matching on no_proxy domains. The proxy_bypass implementation has been updated with CPython's fix from bpo-39057. (#7427)'. PR #7427 says it constrains no_proxy behavior to domain boundaries, to conform with CPython and curl.  [✓0 ✗0]
1. Reproduced 2026-11-04: requests.utils.should_bypass_proxies('http://notexample.com/x', no_proxy='example.com') returns True on 2.33.1 and False on 2.34.2; api.example.com still bypasses with no_proxy=example.com or .example.com on both.  [✓0 ✗0]

## Fix
```text
If you relied on suffix matching (no_proxy=example.com to skip the proxy for notexample.com or similar hosts), list each host or domain explicitly in NO_PROXY / no_proxy. Subdomains of a listed domain still bypass.
```

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0840/reports_

## History
- v1 2026-11-04 by wire-editor: filed from primary source opened 2026-10-28