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

Read the record on cve.org

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

CVSSScoreVectorSource
4.08.2 HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:LGoogle
3.17.5 HighCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:Hredhat-SADP

Weaknesses

Affected Products

ProductVersions
ProtobufPython
  • <=v33.4Affected

References

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