Ubuntu Security Notices USN-8063-2 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. Releases 20.04 LTS 18.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Related notices 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 Ubuntu Pro Fix available with Ubuntu Pro . python-protobuf – 3.6.1.3-2ubuntu5.2+esm3 Ubuntu Pro Fix available with Ubuntu Pro . python3-protobuf – 3.6.1.3-2ubuntu5.2+esm3 Ubuntu Pro Fix available with Ubuntu Pro . 18.04 LTS bionic libprotobuf10 – 3.0.0-9.1ubuntu1.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro . python-protobuf – 3.0.0-9.1ubuntu1.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro . python3-protobuf – 3.0.0-9.1ubuntu1.1+esm4 Ubuntu Pro Fix available with Ubuntu Pro . Reduce your security exposure Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines. Get Ubuntu Pro References CVE-2026-0994 CVE-2026-0994 Related notices USN-8063-1 USN-8063-1