Application crash via unchecked recursive decoding
Published Jun 16, 2025 · Updated Jun 16, 2025
Denial of service in Google Protocol Buffers Python before 4.25.8, 5.29.5, or 6.31.1 allows remote attackers to crash applications. The pure-Python decoder recursively parses nested messages, groups, and SGROUP tags without enforcing a depth limit, eventually raising RecursionError. Exposure requires an application to parse untrusted data with the pure-Python backend selected explicitly, supplied by Bazel, or loaded from a pure-Python wheel.
Summary
What happened
Denial of service in Google Protocol Buffers Python before 4.25.8, 5.29.5, or 6.31.1 allows remote attackers to crash applications. The pure-Python decoder recursively parses nested messages, groups, and SGROUP tags without enforcing a depth limit, eventually raising RecursionError. Exposure requires an application to parse untrusted data with the pure-Python backend selected explicitly, supplied by Bazel, or loaded from a pure-Python wheel.
The record
- CVE
- CVE-2025-4565
- Published
- Jun 16, 2025
- Updated
- Jun 16, 2025
- Vendor
- Product
- Protocol Buffers Python
- Classifications
- CWE-674, T1499.004
- Attack vector
- network
- Privileges
- unauthenticated
Timeline
How it unfolded
- Jun 16, 2025CVE publishedPublication date reported by the CVE source.
- Jun 16, 2025Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=0 <4.25.8
- Affected versionversion=0 <5.29.5
- Affected versionversion=0 <6.31.1
What conditions does exploitation require?
What is affected?
Published CVSS scores
CVSS describes severity. EPSS estimates exploitation probability.
Attacks
What attackers are doing with it
Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.
Weakness, pattern, technique
Public exploit references
- Upstream recursive parsing unit-test reproducerproof of concept · demonstrated
Labels summarize the accepted research assessment. They do not indicate a test against your environment.
Technologies
Your stack
See the directory against your own environment.
Your stack
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