CVE-2025-4565 HIGH

CVE-2025-4565: Unbounded recursion in Python Protobuf

Vendor Protocolbuffers
Product Python-Protobuf
Weakness CWE-674
Published June 16, 2025
Last update June 16, 2025

CVSS base score

8.2/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality
Integrity

CVSS vector

CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N

What the vulnerability does

Description

Any project that uses Protobuf Pure-Python backend to parse untrusted Protocol Buffers data containing an arbitrary number of recursive groups, recursive messages or a series of SGROUP tags can be corrupted by exceeding the Python recursion limit. This can result in a Denial of service by crashing the application with a RecursionError. We recommend upgrading to version =>6.31.1 or beyond commit 17838beda2943d08b8a9d4df5b68f5f04f26d901

Key dates

Disclosure timeline

June 16, 2025 CVE published
June 16, 2025 Record updated