Vulnerability in Google Protobuf-Python
CVE-2025-4565
Any project that uses Protobuf Pure-Python backend to parse untrusted Protocol Buffers data containing an arbitrary number of recursive groups, recursive messages or a series of SGROUP tags can be corrupted by exceeding the Python recursion limit. This can result in a Denial of service by crashing the application with a RecursionError. We recommend upgrading to version =>6.31.1 or beyond commit 17838beda2943d08b8a9d4df5b68f5f04f26d901
EPSS: 0.003 (16.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.3 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve-coordination@google.com (Patch)
Frequently asked questions
- What is CVE-2025-4565?
- CVE-2025-4565 is a medium-severity vulnerability in Google Protobuf-Python, classified under Uncontrolled Recursion. CVSS score: 5.3/10. Published 2025-06-16.
- How severe is CVE-2025-4565?
- Medium severity. CVSS v3 base score is 5.3 out of 10.
- Is CVE-2025-4565 known to be exploited?
- 5 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.