CVE-2025-4565

CVE-2025-4565 is a medium-severity vulnerability in Google Protobuf-python with a CVSS 3.x base score of 5.3. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-674.

Key facts

Description

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

Frequently asked questions

What is 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
How severe is CVE-2025-4565?
CVE-2025-4565 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity none, and availability low.
Is CVE-2025-4565 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (20th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2025-4565?
CVE-2025-4565 affects Google Protobuf-python. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2025-4565?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
Does CVE-2025-4565 have an EU (EUVD) identifier?
Yes. CVE-2025-4565 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-18401.
When was CVE-2025-4565 published?
CVE-2025-4565 was published on 2025-06-16 and last updated on 2026-06-17.

References

Affected products (1)

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