# CVE-2021-22569

## Summary

- **CVE ID:** CVE-2021-22569
- **Severity:** HIGH
- **CVSS Score:** 7.5 (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
- **CWE:** CWE-696
- **Published:** Jan 7, 2022
- **Last Modified:** Mar 13, 2026

## Description

An issue in protobuf-java allowed the interleaving of com.google.protobuf.UnknownFieldSet fields in such a way that would be processed out of order. A small malicious payload can occupy the parser for several minutes by creating large numbers of short-lived objects that cause frequent, repeated pauses. We recommend upgrading libraries beyond the vulnerable versions.

## Affected Products

- Google LLC — protobuf-java (unspecified)
- Google LLC — protobuf-kotlin (unspecified)
- Google LLC — google-protobuf [JRuby Gem] (unspecified)

## References

- [CNA](https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=39330)
- [CNA](https://cloud.google.com/support/bulletins#gcp-2022-001)
- [CNA](http://www.openwall.com/lists/oss-security/2022/01/12/4)
- [CNA](http://www.openwall.com/lists/oss-security/2022/01/12/7)
- [CNA](https://www.oracle.com/security-alerts/cpuapr2022.html)
- [CNA](https://lists.debian.org/debian-lts-announce/2023/04/msg00019.html)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.29%
- **EPSS Percentile:** 52.1

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_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._