High severity · published Jan 23, 2026
CVE-2026-0994
Denial of Service in Python Protobuf
7.5
CVSS
0.7%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.7% · higher than 53% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
PR
Protobuf · Python
<=v33.4 · source: vendor, NVD
RH
Red Hat AI Inference Server 3.2 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat AI Inference Server 3.3 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Ansible Automation Platform 2.5 for RHEL 8 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Ansible Automation Platform 2.5 for RHEL 9 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Ansible Automation Platform 2.6 for RHEL 9 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 10.0 Extended Update Support · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 9 · Red Hat
All versions, or not specified · source: CISA
RH
Red Hat Enterprise Linux 9.4 Extended Update Support · Red Hat
All versions, or not specified · source: CISA