How severe is CVE-2022-41881?

CVE-2022-41881 has a CVSS score of 5.3/10, rated MEDIUM. Review your exposure and patch according to your risk tolerance.

Which packages are affected by CVE-2022-41881?

CVE-2022-41881 affects the following packages: io.netty:netty-codec-haproxy (Maven). Ecosystems affected: Maven.

How do I fix CVE-2022-41881?

Update io.netty:netty-codec-haproxy to 4.1.86.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-41881 is resolved across your whole dependency graph.

How do I detect CVE-2022-41881 in my Maven dependencies?

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

How do I mitigate CVE-2022-41881 if there is no patch (or I can't update yet)?

Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

Is CVE-2022-41881 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2022-41881, 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-2022-41881?

CVE-2022-41881 has an EPSS (Exploit Prediction Scoring System) score of 1.6%, placing it in the 76th 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-2022-41881?

CVE-2022-41881 is classified as CWE-674 (CWE-674). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2022-41881 published, and has it been updated?

CVE-2022-41881 was published on December 12, 2022 and was last updated on October 28, 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

Not in CISA KEV

MEDIUM severity

CVE-2022-41881 — netty-codec-haproxy

MEDIUM

CVE-2022-41881 is a medium-severity (CVSS 5.3) CWE-674 vulnerability in io.netty:netty-codec-haproxy. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for io.netty:netty-codec-haproxy — see the affected versions and patch details below.

HAProxyMessageDecoder Stack Exhaustion DoS

Also known asGHSA-fx2c-96vj-985v

Published

Dec 12, 2022

Updated

Oct 28, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Nov 10, 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-2022-41881.

EPSS Exploitation Probability

via FIRST.org ↗

1.6%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs76th percentile — riskier than 76% 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

1 pkg affected

☕io.netty:netty-codec-haproxy

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

Impact

A StackOverflowError can be raised when parsing a malformed crafted message due to an infinite recursion.

Patches

Users should upgrade to 4.1.86.Final.

Workarounds

There is no workaround, except using a custom HaProxyMessageDecoder.

References

When parsing a TLV with type = PP2_TYPE_SSL, the value can be again a TLV with type = PP2_TYPE_SSL and so on. The only limitation of the recursion is that the TLV length cannot be bigger than 0xffff because it is encoded in an unsigned short type. Providing a TLV with a nesting level that is large enough will lead to raising of a StackOverflowError. The StackOverflowError will be caught if HAProxyMessageDecoder is used as part of Netty’s ChannelPipeline, but using it directly without the ChannelPipeline will lead to a thrown exception / crash.

For more information

If you have any questions or comments about this advisory:

Open an issue in netty

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
☕Maven	`io.netty:netty-codec-haproxy`	all versions	4.1.86.Final`io.netty:netty-codec-haproxy:4.1.86.Final`

Affected Products

2 products · 3 configurations

debian linuxdebian

2 versions

10.011.0

Application

nettynetty

< 4.1.86

range

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.

Netty project is an event-driven asynchronous network application framew…

github.comNVDDec 2022

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for io.netty:netty-codec-haproxy, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update io.netty:netty-codec-haproxy to 4.1.86.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-41881 is resolved across your whole dependency graph.
Workarounds
Stop feeding it untrusted input: reject or quarantine files and payloads from unverified sources until you can upgrade, restrict accepted formats to the ones you actually need, and run the parsing or decoding step in a least-privileged sandbox or short-lived worker so a crash or corrupted read cannot reach the rest of the process.

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
CEQ 2.13.2-1	`codec-haproxy`	RHSA-2023:0888
Migration Toolkit for Runtimes 1 on RHEL 8	`mtr/mtr-web-container-rhel8:1.1-7`	RHSA-2023:3373
Migration Toolkit for Runtimes 1 on RHEL 8	`io.netty-netty-parent`	RHSA-2023:3374
MTA-6.2-RHEL-9	`mta/mta-windup-addon-rhel9:6.2.0-11`	RHSA-2023:4627
Red Hat build of Eclipse Vert.x 4.3.7	`codec-haproxy`	RHSA-2023:0577
Red Hat build of Quarkus	see advisory	RHSA-2023:0758
Red Hat Data Grid 8.4.1	`codec-haproxy`	RHSA-2023:0713
Red Hat Fuse 7.12	`codec-haproxy`	RHSA-2023:3954

UbuntuMEDIUM

USN-6049-1Ubuntu

Frequently Asked Questions

### Impact A StackOverflowError can be raised when parsing a malformed crafted message due to an infinite recursion. ### Patches Users should upgrade to 4.1.86.Final. ### Workarounds There is no workaround, except using a custom HaProxyMessageDecoder. ### References When parsing a TLV with type = PP2_TYPE_SSL, the value can be again a TLV with type = PP2_TYPE_SSL and so on. The only limitation of the recursion is that the TLV length cannot be bigger than 0xffff because it is encoded in an unsigned short type. Providing a TLV with a nesting level that is large enough will lead to raising of