CVE-2025-4565: PYSEC-2026-1806 - protobuf-python has a potential Denial of Service issue

CVE-2025-4565 · Severity: medium · CVSS 4 · Published 2026-07-07

protobuf-python has a potential Denial of Service issue

Technologies: protobuf (PyPI). Vendors: PyPI.

Quick answers

Is CVE-2025-4565 exploited in the wild?
No. Junglewise Threat Intelligence has no report of CVE-2025-4565 being exploited in the wild.
How severe is CVE-2025-4565?
Medium severity, with a CVSS score of 4, published 7 July 2026.
Which products and versions are affected?
protobuf (PyPI) ECOSYSTEM:introduced=0,fixed=4.25.8, ECOSYSTEM:introduced=0,fixed=4.25.8,introduced=5.26.0rc1,fixed=5.29.5,introduced=6.30.0rc1,fixed=6.31.1.
Is there a fix for CVE-2025-4565?
Yes. protobuf (PyPI): upgrade to 4.25.8, 6.31.1 or later. Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
Am I affected by CVE-2025-4565?
Check whether you run protobuf (PyPI) at an affected version. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

How to fix

  • protobuf (PyPI): upgrade to 4.25.8, 6.31.1 or later
    pip install "protobuf>=6.31.1"

Affected products

  • protobuf (PyPI) ECOSYSTEM:introduced=0,fixed=4.25.8, ECOSYSTEM:introduced=0,fixed=4.25.8,introduced=5.26.0rc1,fixed=5.29.5,introduced=6.30.0rc1,fixed=6.31.1

Identifiers

  • CVE-2025-4565
  • GHSA-8qvm-5x2c-j2w7
  • PYSEC-2026-1806

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