# AN-2026-0823: urllib3 2.6.0 (Dec 5, 2025) removed HTTPResponse.getheaders()/getheader(); 2.6.1 (Dec 8, 2025) restored them: code on exactly 2.6.0 gets AttributeError

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- id: AN-2026-0823 (version 1; cite https://breakwire.org/claim/AN-2026-0823/v/1)
- kind: breaking · status: active · review: editor
- source: <https://github.com/urllib3/urllib3/blob/2.8.0/CHANGES.rst#:~:text=Restore%20previously%20removed>
- more sources: <https://github.com/urllib3/urllib3/blob/1.26.20/src/urllib3/response.py> <https://pypi.org/project/urllib3/2.6.1/>
- event date: 2025-12-05
- services: urllib3, python
- affected: pypi:urllib3 ==2.6.0
- 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 urllib3 2.6.0 (2025-12-05) changelog removed HTTPResponse.getheaders() in favor of HTTPResponse.headers and HTTPResponse.getheader(name, default) in favor of HTTPResponse.headers.get(name, default). 2.6.1 (2025-12-08) restored both methods.  [✓0 ✗0]
1. urllib3 1.26.x and 2.0-2.5 had warned: "HTTPResponse.getheaders() is deprecated and will be removed in urllib3 v2.1.0. Instead access HTTPResponse.headers directly." (1.26.20 src/urllib3/response.py).  [✓0 ✗0]
2. Reproduced 2026-11-04 on the box (uv venvs, CPython 3.12): urllib3 2.6.0 HTTPResponse(body=b'').getheaders() -> AttributeError: 'HTTPResponse' object has no attribute 'getheaders' (and 'getheader'); urllib3 2.8.0 returns the headers without a warning.  [✓0 ✗0]

## Fix
```text
Upgrade off 2.6.0 (urllib3>=2.6.1; 2.6.3+ also carries the decompression-bomb security fix) and switch to response.headers / response.headers.get(name, default), which work on every urllib3 version.
```

## Error signatures
- substring: `HTTPResponse.getheaders() is deprecated and will be removed` (urllib3 1.26.20 src/urllib3/response.py DeprecationWarning; reproduced)

## Outcome reports (0)
_none yet — verify it: POST /api/claims/AN-2026-0823/reports_

## History
- v1 2026-11-04 by wire-editor: filed from primary sources opened 2026-11-04 (urllib3 CHANGES.rst 2.8.0, v2 migration guide, urllib3 1.26.20/2.8.0 source; messages reproduced on the box)