Denial of Service in Python Protobuf

Summary

CVECVE-2026-0994
StatePUBLISHED
AssignerGoogle
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-01-23 15:16:06 UTC
Updated2026-06-30 03:17:06 UTC
DescriptionA 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.

Risk And Classification

Primary CVSS: v4.0 8.2 HIGH from [email protected]

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS: 0.006130000 probability, percentile 0.449090000 (date 2026-07-01)

Problem Types: CWE-674 | CWE-674 CWE-674: Uncontrolled Recursion | CWE-674 Uncontrolled Recursion


VersionSourceTypeScoreSeverityVector
4.0[email protected]Secondary8.2HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/C...
4.0CNACVSS8.2HIGHCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
3.1[email protected]Primary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.1ADPCVSS7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
3.10b0ca135-0b70-47e7-9f44-1890c2a1c46cSecondary7.5HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CVSS v4.0 Breakdown

Attack Vector
Network
Attack Complexity
Low
Attack Requirements
Present
Privileges Required
None
User Interaction
None
Confidentiality
None
Integrity
None
Availability
High
Sub Conf.
None
Sub Integrity
None
Sub Availability
Low

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/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

CVSS v3.1 Breakdown

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

NVD Known Affected Configurations (CPE 2.3)

TypeVendorProductVersionUpdateEditionLanguage
Application Google Protobuf All All All All

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Python Protobuf affected <=v33.4 custom Not specified
ADP Red Hat Red Hat Ansible Automation Platform 2.5 For RHEL 8 Not specified Not specified
ADP Red Hat Red Hat Ansible Automation Platform 2.5 For RHEL 9 Not specified Not specified
ADP Red Hat Red Hat Ansible Automation Platform 2.6 For RHEL 9 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AppStream EUS V. 10.0 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AppStream V. 10 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AppStream E4S V.9.0 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AppStream E4S V.9.2 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AppStream EUS V.9.4 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AppStream EUS V.9.6 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux AppStream V. 9 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux CodeReady Linux Builder EUS V. 10.0 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux CodeReady Linux Builder V. 10 Not specified Not specified
ADP Red Hat Red Hat CodeReady Linux Builder EUS V.9.4 Not specified Not specified
ADP Red Hat Red Hat CodeReady Linux Builder EUS V.9.6 Not specified Not specified
ADP Red Hat Red Hat Enterprise Linux CodeReady Linux Builder V. 9 Not specified Not specified
ADP Red Hat Red Hat AI Inference Server 3.2 Not specified Not specified
ADP Red Hat Red Hat AI Inference Server 3.3 Not specified Not specified
ADP Red Hat Red Hat Ansible Automation Platform 2.6 For RHEL 10 Not specified Not specified
ADP Red Hat Red Hat AMQ Clients Not specified Not specified
ADP Red Hat Red Hat Ansible Automation Platform 2 Not specified Not specified
ADP Red Hat Red Hat Hardened Images Not specified Not specified
ADP Red Hat Red Hat OpenStack Platform 16.2 Not specified Not specified

References

ReferenceSourceLinkTags
access.redhat.com/errata/RHSA-2026:3958 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3462 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:8747 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3219 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3095 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3097 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3059 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:16174 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
bugzilla.redhat.com/show_bug.cgi 0b0ca135-0b70-47e7-9f44-1890c2a1c46c bugzilla.redhat.com
access.redhat.com/errata/RHSA-2026:3094 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3220 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3218 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/security/cve/CVE-2026-0994 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:8746 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:8748 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0994.json 0b0ca135-0b70-47e7-9f44-1890c2a1c46c security.access.redhat.com
access.redhat.com/errata/RHSA-2026:3461 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
access.redhat.com/errata/RHSA-2026:3959 0b0ca135-0b70-47e7-9f44-1890c2a1c46c access.redhat.com
github.com/protocolbuffers/protobuf/pull/25239 [email protected] github.com Patch, Vendor Advisory
CVE Program record CVE.ORG www.cve.org canonical
NVD vulnerability detail NVD nvd.nist.gov canonical, analysis

Additional Advisory Data

SourceTimeEvent
ADP2026-01-23T16:02:59.235ZReported to Red Hat.
ADP2026-01-23T14:55:16.876ZMade public.

Solutions

ADP: RHSA-2026:3959: Red Hat Ansible Automation Platform 2.5 for RHEL 8, Red Hat Ansible Automation Platform 2.5 for RHEL 9

ADP: RHSA-2026:3958: Red Hat Ansible Automation Platform 2.6 for RHEL 9

ADP: RHSA-2026:3218: Red Hat Enterprise Linux AppStream EUS (v. 10.0), Red Hat Enterprise Linux CodeReady Linux Builder EUS (v. 10.0)

ADP: RHSA-2026:3094: Red Hat Enterprise Linux AppStream (v. 10), Red Hat Enterprise Linux CodeReady Linux Builder (v. 10)

ADP: RHSA-2026:3097: Red Hat Enterprise Linux AppStream E4S (v.9.0)

ADP: RHSA-2026:3220: Red Hat Enterprise Linux AppStream E4S (v.9.2)

ADP: RHSA-2026:3059: Red Hat CodeReady Linux Builder EUS (v.9.4), Red Hat Enterprise Linux AppStream EUS (v.9.4)

ADP: RHSA-2026:3219: Red Hat CodeReady Linux Builder EUS (v.9.6), Red Hat Enterprise Linux AppStream EUS (v.9.6)

ADP: RHSA-2026:3095: Red Hat Enterprise Linux AppStream (v. 9), Red Hat Enterprise Linux CodeReady Linux Builder (v. 9)

ADP: RHSA-2026:3461: Red Hat AI Inference Server 3.2

ADP: RHSA-2026:3462: Red Hat AI Inference Server 3.2

ADP: RHSA-2026:8748: Red Hat AI Inference Server 3.3

ADP: RHSA-2026:8746: Red Hat AI Inference Server 3.3

ADP: RHSA-2026:8747: Red Hat AI Inference Server 3.3

ADP: RHSA-2026:16174: Red Hat AI Inference Server 3.3

Workarounds

ADP: Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.

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