How severe is CVE-2021-22569?

CVE-2021-22569 has a CVSS score of 5.5/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2021-22569?

CVE-2021-22569 affects the following packages: com.google.protobuf:protobuf-java (Maven), com.google.protobuf:protobuf-java (Maven), com.google.protobuf:protobuf-java (Maven), com.google.protobuf:protobuf-kotlin (Maven), com.google.protobuf:protobuf-kotlin (Maven), google-protobuf (RubyGems). Ecosystems affected: Maven, RubyGems.

How do I fix CVE-2021-22569?

Update com.google.protobuf:protobuf-java to 3.16.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-22569 is resolved across your whole dependency graph.

How do I detect CVE-2021-22569 in my Maven, RubyGems dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.google.protobuf:protobuf-java, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-22569 if there is no patch (or I can't update yet)?

Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Is CVE-2021-22569 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2021-22569, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2021-22569?

CVE-2021-22569 has an EPSS (Exploit Prediction Scoring System) score of 1.8%, placing it in the 78th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-22569?

CVE-2021-22569 is classified as CWE-696 (CWE-696). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-22569 published, and has it been updated?

CVE-2021-22569 was published on January 10, 2022 and was last updated on October 24, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

☕

☕ Maven💎 RubyGems

Not in CISA KEV

MEDIUM severity

CVE-2021-22569 — protobuf-java

MEDIUM

CVE-2021-22569 is a medium-severity (CVSS 5.5) CWE-696 vulnerability in com.google.protobuf:protobuf-java. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for com.google.protobuf:protobuf-java — see the affected versions and patch details below.

A potential Denial of Service issue in protobuf-java

Also known asGHSA-wrvw-hg22-4m67

Published

Jan 10, 2022

Updated

Oct 24, 2026

Affected

6 pkgs

Patched

6 / 6

Exploits

1 known

Exploitation data as of Nov 3, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

Proof-of-concept exploit code exists

CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.

Exploitation and automatability from CISA’s SSVC triage for CVE-2021-22569.

EPSS Exploitation Probability

via FIRST.org ↗

1.8%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs78th percentile — riskier than 78% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

6 pkgs affected

☕com.google.protobuf:protobuf-java☕com.google.protobuf:protobuf-java☕com.google.protobuf:protobuf-java☕com.google.protobuf:protobuf-kotlin☕com.google.protobuf:protobuf-kotlin💎google-protobuf

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Summary

A potential Denial of Service issue in protobuf-java was discovered in the parsing procedure for binary data.

Reporter: OSS-Fuzz

Affected versions: All versions of Java Protobufs (including Kotlin and JRuby) prior to the versions listed below. Protobuf "javalite" users (typically Android) are not affected.

Severity

CVE-2021-22569 High - CVSS Score: 7.5, An implementation weakness in how unknown fields are parsed in Java. A small (~800 KB) malicious payload can occupy the parser for several minutes by creating large numbers of short-lived objects that cause frequent, repeated GC pauses.

Proof of Concept

For reproduction details, please refer to the oss-fuzz issue that identifies the specific inputs that exercise this parsing weakness.

Remediation and Mitigation

Please update to the latest available versions of the following packages:

protobuf-java (3.16.1, 3.18.2, 3.19.2)
protobuf-kotlin (3.18.2, 3.19.2)
google-protobuf [JRuby gem only] (3.19.2)

Affected Packages

6 total 6 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`com.google.protobuf:protobuf-java`	all versions	3.16.1`com.google.protobuf:protobuf-java:3.16.1`
☕Maven	`com.google.protobuf:protobuf-java`	≥ 3.18.0&&< 3.18.2	3.18.2`com.google.protobuf:protobuf-java:3.18.2`
☕Maven	`com.google.protobuf:protobuf-java`	≥ 3.19.0&&< 3.19.2	3.19.2`com.google.protobuf:protobuf-java:3.19.2`
☕Maven	`com.google.protobuf:protobuf-kotlin`	≥ 3.18.0&&< 3.18.2	3.18.2`com.google.protobuf:protobuf-kotlin:3.18.2`
☕Maven	`com.google.protobuf:protobuf-kotlin`	≥ 3.19.0&&< 3.19.2	3.19.2`com.google.protobuf:protobuf-kotlin:3.19.2`
💎RubyGems	`google-protobuf`	all versions	3.19.2`bundle update google-protobuf --conservative`

Affected Products

7 products · 12 configurations

Application

google-protobufgoogle

< 3.19.2

range

Application

protobuf-javagoogle

≥ 3.19.0 && < 3.19.2

range

Application

protobuf-kotlingoogle

≥ 3.19.0 && < 3.19.2

range

Application

communications cloud native core consoleoracle

1 version

1.9.0

Application

communications cloud native core network repository functionoracle

2 versions

1.15.01.15.1

Application

communications cloud native core policyoracle

1 version

1.15.0

Exploits & PoCs

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

An issue in protobuf-java allowed the interleaving of com.google.protobu…

bugs.chromium.orgNVDJan 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for com.google.protobuf:protobuf-java, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update com.google.protobuf:protobuf-java to 3.16.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-22569 is resolved across your whole dependency graph.
Workarounds
Cap what an attacker can consume: apply request size, rate and timeout limits in front of the affected component, and run it with memory and CPU limits so exhaustion degrades one worker rather than the whole service.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
Red Hat build of Quarkus 2.7.5	`protobuf-java`	RHSA-2022:4623
Red Hat Fuse 7.11	`protobuf-java`	RHSA-2022:5532
RHINT Camel-Q 2.2.1	see advisory	RHSA-2022:1013
RHINT Debezium 1.9.7	`protobuf-java`	RHSA-2022:7896
RHINT Service Registry 2.3.0 GA	`protobuf-java`	RHSA-2022:6835
RHPAM 7.13.0 async	`protobuf-java`	RHSA-2022:5903
Text-Only RHOAR	`protobuf-java`	RHSA-2022:8761

Frequently Asked Questions

## Summary A potential Denial of Service issue in protobuf-java was discovered in the parsing procedure for binary data. Reporter: [OSS-Fuzz](https://github.com/google/oss-fuzz) Affected versions: All versions of Java Protobufs (including Kotlin and JRuby) prior to the versions listed below. Protobuf "javalite" users (typically Android) are not affected. ## Severity [CVE-2021-22569](https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-22569) **High** - CVSS Score: 7.5, An implementation weakness in how unknown fields are parsed in Java. A small (~800 KB) malicious payload can occupy t

O3 Security · Impact-Aware SCA

Is CVE-2021-22569 in your dependencies?

Find it across Maven, RubyGems, including transitive dependencies.

Scan my dependencies How O3 SCA works

CVSS Score

5.5/10CVSS v3 base

Vector breakdown

Attack Vector

Local

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Unchanged

Confidentiality

None

Integrity

None

Availability

High

Raw vector

CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H

CWE Classification

CWE-696CWE-696

Weaponization

No Nuclei template or Metasploit module yet. 1 public proof-of-concept reference is listed on this page.

OpenSSF Scorecard

Package health score

protobuf

6.2/10

Code-Review1/10

Dependency-Update-Tool10/10

Maintained10/10

Branch-ProtectionN/A

Vulnerabilities6/10

Assessed Nov 4, 2026

Timeline

Disclosed

Jan 10, 2022

First exploit

Jan 14, 2022

4 days after disclosure — rapid exploitation

Last updated

Oct 24, 2026

Identifiers

CVE-2021-22569

GHSA-wrvw-hg22-4m67

References

Advisoryopenwall.com Advisoryopenwall.com Advisorycloud.google.com · bulletins Advisorynvd.nist.gov · CVE 2021 22569 Fixoracle.com · cpuapr2022 Reportbugs.chromium.org · detail Weblists.debian.org · msg00019 Webgithub.com · GHSA wrvw hg22 4m67 Packagegithub.com · protobuf

Related vulnerabilities

Also affects protobuf-java

This CVE is medium severity; 4 of 4 other CVEs affecting protobuf-java are rated as high or higher (top: high).

CVE-2024-7254CVE-2022-3510CVE-2022-3509CVE-2022-3171

Same weakness: CWE-696

This CVE is medium severity; 4 of 4 other CVEs with CWE-696 are rated as high or higher (top: high).

CVE-2026-114145CVE-2026-105745CVE-2026-26287GHSA-p634-w6r4-rjp2Browse all CWE-696

Provenance

Sources

OSV.devNVDFIRST.org (EPSS)

Last verifiedOct 24, 2026

CVE-2021-22569 — protobuf-java

Exploitation Status

Proof-of-concept exploit code exists

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Real-World Exposure

Description

Summary

Severity

Proof of Concept

Remediation and Mitigation

Affected Packages

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Fixing This On Your OS

Frequently Asked Questions

Is CVE-2021-22569 in your dependencies?