This PR contains the following updates:

| Package | Change |
[Age](https://docs.renovatebot.com/merge-confidence/) |
[Confidence](https://docs.renovatebot.com/merge-confidence/) |
|---|---|---|---|
| [urllib3](https://redirect.github.com/urllib3/urllib3)
([changelog](https://redirect.github.com/urllib3/urllib3/blob/main/CHANGES.rst))
| `==2.5.0` -> `==2.6.0` |
![age](https://developer.mend.io/api/mc/badges/age/pypi/urllib3/2.6.0?slim=true)
|
![confidence](https://developer.mend.io/api/mc/badges/confidence/pypi/urllib3/2.5.0/2.6.0?slim=true)
|

### GitHub Vulnerability Alerts

####
[CVE-2025-66418](https://redirect.github.com/urllib3/urllib3/security/advisories/GHSA-gm62-xv2j-4w53)

## Impact

urllib3 supports chained HTTP encoding algorithms for response content
according to RFC 9110 (e.g., `Content-Encoding: gzip, zstd`).

However, the number of links in the decompression chain was unbounded
allowing a malicious server to insert a virtually unlimited number of
compression steps leading to high CPU usage and massive memory
allocation for the decompressed data.

## Affected usages

Applications and libraries using urllib3 version 2.5.0 and earlier for
HTTP requests to untrusted sources unless they disable content decoding
explicitly.

## Remediation

Upgrade to at least urllib3 v2.6.0 in which the library limits the
number of links to 5.

If upgrading is not immediately possible, use
[`preload_content=False`](https://urllib3.readthedocs.io/en/2.5.0/advanced-usage.html#streaming-and-i-o)
and ensure that `resp.headers["content-encoding"]` contains a safe
number of encodings before reading the response content.

####
[CVE-2025-66471](https://redirect.github.com/urllib3/urllib3/security/advisories/GHSA-2xpw-w6gg-jr37)

### Impact

urllib3's [streaming
API](https://urllib3.readthedocs.io/en/2.5.0/advanced-usage.html#streaming-and-i-o)
is designed for the efficient handling of large HTTP responses by
reading the content in chunks, rather than loading the entire response
body into memory at once.

When streaming a compressed response, urllib3 can perform decoding or
decompression based on the HTTP `Content-Encoding` header (e.g., `gzip`,
`deflate`, `br`, or `zstd`). The library must read compressed data from
the network and decompress it until the requested chunk size is met. Any
resulting decompressed data that exceeds the requested amount is held in
an internal buffer for the next read operation.

The decompression logic could cause urllib3 to fully decode a small
amount of highly compressed data in a single operation. This can result
in excessive resource consumption (high CPU usage and massive memory
allocation for the decompressed data; CWE-409) on the client side, even
if the application only requested a small chunk of data.

### Affected usages

Applications and libraries using urllib3 version 2.5.0 and earlier to
stream large compressed responses or content from untrusted sources.

`stream()`, `read(amt=256)`, `read1(amt=256)`, `read_chunked(amt=256)`,
`readinto(b)` are examples of `urllib3.HTTPResponse` method calls using
the affected logic unless decoding is disabled explicitly.

### Remediation

Upgrade to at least urllib3 v2.6.0 in which the library avoids
decompressing data that exceeds the requested amount.

If your environment contains a package facilitating the Brotli encoding,
upgrade to at least Brotli 1.2.0 or brotlicffi 1.2.0.0 too. These
versions are enforced by the `urllib3[brotli]` extra in the patched
versions of urllib3.

### Credits

The issue was reported by @​Cycloctane.
Supplemental information was provided by @​stamparm during a
security audit performed by [7ASecurity](https://7asecurity.com/) and
facilitated by [OSTIF](https://ostif.org/).

---

### Release Notes

<details>
<summary>urllib3/urllib3 (urllib3)</summary>

###
[`v2.6.0`](https://redirect.github.com/urllib3/urllib3/blob/HEAD/CHANGES.rst#260-2025-12-05)

[Compare
Source](https://redirect.github.com/urllib3/urllib3/compare/2.5.0...2.6.0)

\==================

## Security

- Fixed a security issue where streaming API could improperly handle
highly
compressed HTTP content ("decompression bombs") leading to excessive
resource
consumption even when a small amount of data was requested. Reading
small
  chunks of compressed data is safer and much more efficient now.
(`GHSA-2xpw-w6gg-jr37
<https://github.com/urllib3/urllib3/security/advisories/GHSA-2xpw-w6gg-jr37>`\_\_)
- Fixed a security issue where an attacker could compose an HTTP
response with
virtually unlimited links in the `Content-Encoding` header, potentially
leading to a denial of service (DoS) attack by exhausting system
resources
during decoding. The number of allowed chained encodings is now limited
to 5.
(`GHSA-gm62-xv2j-4w53
<https://github.com/urllib3/urllib3/security/advisories/GHSA-gm62-xv2j-4w53>`\_\_)

.. caution::

- If urllib3 is not installed with the optional `urllib3[brotli]` extra,
but
your environment contains a Brotli/brotlicffi/brotlipy package anyway,
make
  sure to upgrade it to at least Brotli 1.2.0 or brotlicffi 1.2.0.0 to
  benefit from the security fixes and avoid warnings. Prefer using
`urllib3[brotli]` to install a compatible Brotli package automatically.

- If you use custom decompressors, please make sure to update them to
  respect the changed API of `urllib3.response.ContentDecoder`.

## Features

- Enabled retrieval, deletion, and membership testing in
`HTTPHeaderDict` using bytes keys. (`#&#8203;3653
<https://github.com/urllib3/urllib3/issues/3653>`\_\_)
- Added host and port information to string representations of
`HTTPConnection`. (`#&#8203;3666
<https://github.com/urllib3/urllib3/issues/3666>`\_\_)
- Added support for Python 3.14 free-threading builds explicitly.
(`#&#8203;3696 <https://github.com/urllib3/urllib3/issues/3696>`\_\_)

## Removals

- Removed the `HTTPResponse.getheaders()` method in favor of
`HTTPResponse.headers`.
Removed the `HTTPResponse.getheader(name, default)` method in favor of
`HTTPResponse.headers.get(name, default)`. (`#&#8203;3622
<https://github.com/urllib3/urllib3/issues/3622>`\_\_)

## Bugfixes

- Fixed redirect handling in `urllib3.PoolManager` when an integer is
passed
for the retries parameter. (`#&#8203;3649
<https://github.com/urllib3/urllib3/issues/3649>`\_\_)
- Fixed `HTTPConnectionPool` when used in Emscripten with no explicit
port. (`#&#8203;3664
<https://github.com/urllib3/urllib3/issues/3664>`\_\_)
- Fixed handling of `SSLKEYLOGFILE` with expandable variables.
(`#&#8203;3700 <https://github.com/urllib3/urllib3/issues/3700>`\_\_)

## Misc

- Changed the `zstd` extra to install `backports.zstd` instead of
`zstandard` on Python 3.13 and before. (`#&#8203;3693
<https://github.com/urllib3/urllib3/issues/3693>`\_\_)
- Improved the performance of content decoding by optimizing
`BytesQueueBuffer` class. (`#&#8203;3710
<https://github.com/urllib3/urllib3/issues/3710>`\_\_)
- Allowed building the urllib3 package with newer setuptools-scm v9.x.
(`#&#8203;3652 <https://github.com/urllib3/urllib3/issues/3652>`\_\_)
- Ensured successful urllib3 builds by setting Hatchling requirement to
>= 1.27.0. (`#&#8203;3638
<https://github.com/urllib3/urllib3/issues/3638>`\_\_)

</details>

---

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---

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Thank you for opening a Pull Request! Before submitting your PR, there
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PR created by the Librarian CLI to initialize a release. Merging this PR
will auto trigger a release.

Librarian Version: v0.7.0
Language Image:
us-central1-docker.pkg.dev/cloud-sdk-librarian-prod/images-prod/python-librarian-generator@sha256:c8612d3fffb3f6a32353b2d1abd16b61e87811866f7ec9d65b59b02eb452a620
<details><summary>google-cloud-bigquery: 3.40.0</summary>

##
[3.40.0](v3.39.0...v3.40.0)
(2026-01-08)

### Features

* support load_table and list_rows with picosecond timestamp (#2351)
([46764a5](46764a59))

* support timestamp_precision in table schema (#2333)
([8d5785a](8d5785ae))

</details>