CVE-2026-0994 HIGH

CVE-2026-0994: Denial of Service in Python Protobuf

Vendor Python
Product Protobuf
Weakness CWE-674
Published January 23, 2026
Last update January 30, 2026

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:L

What the vulnerability does

Description

A denial-of-service (DoS) vulnerability exists in google.protobuf.json_format.ParseDict() in Python, where the max_recursion_depth limit can be bypassed when parsing nested google.protobuf.Any messages. Due to missing recursion depth accounting inside the internal Any-handling logic, an attacker can supply deeply nested Any structures that bypass the intended recursion limit, eventually exhausting Python’s recursion stack and causing a RecursionError.

Key dates

Disclosure timeline

January 23, 2026 CVE published
January 30, 2026 Record updated