CVE-2026-0994
Denial of Service in Python Protobuf
- State
- Published
- Severity
- 8.2 High
- Published
- Jan 23, 2026
- Updated
- Sep 1, 2026
- Reserved
- Jan 15, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 8.2 High | 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 | |
| 3.1 | 7.5 High | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H | redhat-SADP |
Weaknesses
- CWE-674 Uncontrolled Recursion
Affected Products
| Product | Versions |
|---|---|
ProtobufPython |
|
References
- https://github.com/protocolbuffers/protobuf/pull/25239
- https://access.redhat.com/security/cve/CVE-2026-0994vdb-entry
- RHBZ#2432398issue-tracking
- https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-0994.json
- https://access.redhat.com/errata/RHSA-2026:3959vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3958vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3218vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3094vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3097vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3220vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3059vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3219vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3095vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:61627vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3461vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:3462vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:61629vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:8748vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:8746vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:8747vendor-advisory
- https://access.redhat.com/errata/RHSA-2026:16174vendor-advisory
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