---
title: "CVE-2025-4565\n    | Ubuntu"
description: Ubuntu is an open source software operating system that runs from the
  desktop, to the cloud, to all your internet connected things.
url: https://ubuntu.com/security/CVE-2025-4565?format=md
keywords: index, follow
---

# CVE-2025-4565

Publication date 16 June 2025

Last updated 16 September 2025

---

Ubuntu priority

**Medium**

[Why this priority?](https://ubuntu.com/security/cves/about#priority )

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## 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

[Read the notes from the security team](https://ubuntu.com/security/CVE-2025-4565?format=md#notes)

## Status

Show unmaintained releases

| Package | Ubuntu Release | Status |
| --- | --- | --- |
| protobuf | 25.04 plucky | Fixed 3.21.12-10ubuntu0.1 |
| 24.10 oracular | Ignored end of life |
| 24.04 LTS noble | Fixed 3.21.12-8.2ubuntu0.2 |
| 22.04 LTS jammy | Fixed 3.12.4-1ubuntu7.22.04.4 |
| 20.04 LTS focal | Fixed 3.6.1.3-2ubuntu5.2+esm2  Ubuntu Pro |
| 18.04 LTS bionic | Fixed 3.0.0-9.1ubuntu1.1+esm3  Ubuntu Pro |
| 16.04 LTS xenial | Fixed 2.6.1-1.3ubuntu0.1~esm4  Ubuntu Pro |
| 14.04 LTS trusty | Ignored changes too intrusive |

---

* [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)
* [What do statuses mean?](https://ubuntu.com/security/cves/about#statuses)
* [Patch details](https://ubuntu.com/security/CVE-2025-4565?format=md#patch-details)

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## Notes

---

### [john-breton](https://launchpad.net/~john-breton)

trusty is on 2.5.0, changes too involved to risk backporting

### Patch details

For informational purposes only. We recommend not to cherry-pick updates. [How can I get the fixes?](https://ubuntu.com/security/cves/about#security)

| Package | Patch details |
| --- | --- |
| protobuf | * Upstream:   [17838be](https://github.com/protocolbuffers/protobuf/commit/17838beda2943d08b8a9d4df5b68f5f04f26d901) |

## References

* [MITRE](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2025-4565)
* [NVD](https://nvd.nist.gov/vuln/detail/CVE-2025-4565)
* [Launchpad](https://launchpad.net/bugs/cve/CVE-2025-4565)
* [Debian](https://security-tracker.debian.org/tracker/CVE-2025-4565)

### Related Ubuntu Security Notices (USN)

+ [USN-7629-1](https://usn.ubuntu.com/USN-7629-1)
+ Protocol Buffers vulnerabilities
+ 9 July 2025

+ [USN-7629-2](https://usn.ubuntu.com/USN-7629-2)
+ Protocol Buffers vulnerabilities
+ 2 September 2025

### Other references

* <https://www.cve.org/CVERecord?id=CVE-2025-4565>