USN-8063-2: Protocol Buffers vulnerability

Publication date

26 May 2026

Overview

Protocol Buffers could be made to consume resources if it received specially crafted input.


Packages

  • protobuf - protocol buffers data serialization library

Details

USN-8063-1 fixed a vulnerability in Protocol Buffers. This update provides
the corresponding update for Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.

Original advisory details:

It was discovered that Protocol Buffers incorrectly handled recursion
when the Python google.protobuf.json_format.ParseDict() function is being
used. An attacker could possibly use this issue to cause Protocol Buffers
to consume resources, resulting in a denial of service.

USN-8063-1 fixed a vulnerability in Protocol Buffers. This update provides
the corresponding update for Ubuntu 18.04 LTS and Ubuntu 20.04 LTS.

Original advisory details:

It was discovered that Protocol Buffers incorrectly handled recursion
when the Python google.protobuf.json_format.ParseDict() function is being
used. An attacker could possibly use this issue to cause Protocol Buffers
to consume resources, resulting in a denial of service.

Update instructions

In general, a standard system update will make all the necessary changes.

Learn more about how to get the fixes.

The problem can be corrected by updating your system to the following package versions:

Ubuntu Release Package Version
20.04 LTS focal libprotobuf17 –  3.6.1.3-2ubuntu5.2+esm3  
python-protobuf –  3.6.1.3-2ubuntu5.2+esm3  
python3-protobuf –  3.6.1.3-2ubuntu5.2+esm3  
18.04 LTS bionic libprotobuf10 –  3.0.0-9.1ubuntu1.1+esm4  
python-protobuf –  3.0.0-9.1ubuntu1.1+esm4  
python3-protobuf –  3.0.0-9.1ubuntu1.1+esm4  

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