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fix(deps): update dependency werkzeug to v3.1.4 [security]#237

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renovate[bot] merged 1 commit intofeature/renovatefrom
feature/pypi-werkzeug-vulnerability
Dec 2, 2025
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fix(deps): update dependency werkzeug to v3.1.4 [security]#237
renovate[bot] merged 1 commit intofeature/renovatefrom
feature/pypi-werkzeug-vulnerability

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@renovate renovate bot commented Dec 2, 2025

This PR contains the following updates:

Package Change Age Confidence
werkzeug (changelog) 3.1.3 -> 3.1.4 age confidence

GitHub Vulnerability Alerts

CVE-2023-25577

Werkzeug's multipart form data parser will parse an unlimited number of parts, including file parts. Parts can be a small amount of bytes, but each requires CPU time to parse and may use more memory as Python data. If a request can be made to an endpoint that accesses request.data, request.form, request.files, or request.get_data(parse_form_data=False), it can cause unexpectedly high resource usage.

This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. The amount of RAM required can trigger an out of memory kill of the process. Unlimited file parts can use up memory and file handles. If many concurrent requests are sent continuously, this can exhaust or kill all available workers.

CVE-2023-23934

Browsers may allow "nameless" cookies that look like =value instead of key=value. A vulnerable browser may allow a compromised application on an adjacent subdomain to exploit this to set a cookie like =__Host-test=bad for another subdomain.

Werkzeug <= 2.2.2 will parse the cookie =__Host-test=bad as __Host-test=bad. If a Werkzeug application is running next to a vulnerable or malicious subdomain which sets such a cookie using a vulnerable browser, the Werkzeug application will see the bad cookie value but the valid cookie key.

CVE-2023-46136

Werkzeug multipart data parser needs to find a boundary that may be between consecutive chunks. That's why parsing is based on looking for newline characters. Unfortunately, code looking for partial boundary in the buffer is written inefficiently, so if we upload a file that starts with CR or LF and then is followed by megabytes of data without these characters: all of these bytes are appended chunk by chunk into internal bytearray and lookup for boundary is performed on growing buffer.

This allows an attacker to cause a denial of service by sending crafted multipart data to an endpoint that will parse it. The amount of CPU time required can block worker processes from handling legitimate requests. The amount of RAM required can trigger an out of memory kill of the process. If many concurrent requests are sent continuously, this can exhaust or kill all available workers.

CVE-2024-34069

The debugger in affected versions of Werkzeug can allow an attacker to execute code on a developer's machine under some circumstances. This requires the attacker to get the developer to interact with a domain and subdomain they control, and enter the debugger PIN, but if they are successful it allows access to the debugger even if it is only running on localhost. This also requires the attacker to guess a URL in the developer's application that will trigger the debugger.

CVE-2024-49767

Applications using Werkzeug to parse multipart/form-data requests are vulnerable to resource exhaustion. A specially crafted form body can bypass the Request.max_form_memory_size setting.

The Request.max_content_length setting, as well as resource limits provided by deployment software and platforms, are also available to limit the resources used during a request. This vulnerability does not affect those settings. All three types of limits should be considered and set appropriately when deploying an application.

CVE-2024-49766

On Python < 3.11 on Windows, os.path.isabs() does not catch UNC paths like //server/share. Werkzeug's safe_join() relies on this check, and so can produce a path that is not safe, potentially allowing unintended access to data. Applications using Python >= 3.11, or not using Windows, are not vulnerable.

CVE-2025-66221

Werkzeug's safe_join function allows path segments with Windows device names. On Windows, there are special device names such as CON, AUX, etc that are implicitly present and readable in every directory. send_from_directory uses safe_join to safely serve files at user-specified paths under a directory. If the application is running on Windows, and the requested path ends with a special device name, the file will be opened successfully, but reading will hang indefinitely.


Release Notes

pallets/werkzeug (werkzeug)

v3.1.4

Compare Source

Released 2025-11-28

  • safe_join on Windows does not allow special device names. This prevents
    reading from these when using send_from_directory. secure_filename
    already prevented writing to these. :ghsa:hgf8-39gv-g3f2
  • The debugger pin fails after 10 attempts instead of 11. :pr:3020
  • The multipart form parser handles a \r\n sequence at a chunk boundary.
    :issue:3065
  • Improve CPU usage during Watchdog reloader. :issue:3054
  • Request.json annotation is more accurate. :issue:3067
  • Traceback rendering handles when the line number is beyond the available
    source lines. :issue:3044
  • HTTPException.get_response annotation and doc better conveys the
    distinction between WSGI and sans-IO responses. :issue:3056

Configuration

📅 Schedule: Branch creation - "" in timezone America/Vancouver, Automerge - At any time (no schedule defined).

🚦 Automerge: Enabled.

Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.


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This PR was generated by Mend Renovate. View the repository job log.

@renovate renovate bot added the renovate Flagged by renovate label Dec 2, 2025
@renovate renovate bot merged commit 0acfb3b into feature/renovate Dec 2, 2025
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@renovate renovate bot deleted the feature/pypi-werkzeug-vulnerability branch December 2, 2025 10:36
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