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Not in CISA KEV
HIGH severity

CVE-2024-5971 — undertow-core

HIGHFix: undertow-io/undertow#1638

CVE-2024-5971 is a high-severity (CVSS 7.5) CWE-674 vulnerability in io.undertow:undertow-core. A fix is available for io.undertow:undertow-core — see the affected versions and patch details below.

Undertow: response write hangs in case of java 17 tlsv1.3 newsessionticket

Also known asGHSA-xpp6-8r3j-ww43
Published
Updated
Affected
2 pkgs
Patched
2 / 2
Exploits
None indexed
Exploitation data as of Nov 6, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

Exploitation Status

No confirmed exploitation observed yet

  • CISA assesses this as automatable — exploitation doesn’t require manual, per-target effort, which raises the odds of mass scanning and opportunistic attacks.
  • CISA’s own triage has not observed active exploitation or public proof-of-concept code for this CVE as of its last assessment.

Exploitation and automatability from CISA’s SSVC triage for CVE-2024-5971.

EPSS Exploitation Probability

via FIRST.org ↗
2.9%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs87th percentile — riskier than 87% of all scored CVEsHighest risk
2.22%2.88%3.54%4.20%3.7%2.9%May 26Sep 26Nov 26

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

2 pkgs affected
☕io.undertow:undertow-core☕io.undertow:undertow-core

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

A vulnerability was found in Undertow, where the chunked response hangs after the body was flushed. The response headers and body were sent but the client would continue waiting as Undertow does not send the expected 0\r\n termination of the chunked response. This results in uncontrolled resource consumption, leaving the server side to a denial of service attack. This happens only with Java 17 TLSv1.3 scenarios.

Affected Packages

2 total 2 fixed
EcosystemPackageVulnerable rangeFix
☕Mavenio.undertow:undertow-core≥ 2.3.0.Alpha1&&< 2.3.15.Final2.3.15.Finalio.undertow:undertow-core:2.3.15.Final
☕Mavenio.undertow:undertow-coreall versions2.2.34.Finalio.undertow:undertow-core:2.2.34.Final

Detection & mitigation playbook

Open-source dependency

  1. Detect

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

  2. Fix

    Update io.undertow:undertow-core to 2.3.15.Final or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-5971 is resolved across your whole dependency graph.

  3. 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 HatImportant

The identified vulnerability in Undertow, where chunked responses fail to terminate properly under Java 17 with TLSv1.3, represents a significant security concern due to its potential for uncontrolled resource consumption and denial of service (DoS) attacks. This issue arises from Undertow's mishandling of chunked…

Workaround published by Red Hat
Mitigation for this issue is either not available or the currently available options don't meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base or stability.
Source: Red Hat security advisory for CVE-2024-5971 (CC BY 4.0)
ProductFixed inAdvisory
Red Hat build of Apache Camel 3.20.7 for Spring BootundertowRHSA-2024:6883
Red Hat build of Apache Camel 4.4.1 for Spring Boot 3.2undertowRHSA-2024:4884
Red Hat build of Apache Camel 4.4.2 for Spring Bootsee advisoryRHSA-2024:6508
Red Hat JBoss Enterprise Application Platformio.undertow/undertow-core:2.2.33.SP1-redhat-00001RHSA-2024:5147
Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 8eap7-undertow-0:2.2.33-1.SP1_redhat_00001.1.el8eapRHSA-2024:5144
Red Hat JBoss Enterprise Application Platform 7.4 for RHEL 9eap7-undertow-0:2.2.33-1.SP1_redhat_00001.1.el9eapRHSA-2024:5145
Red Hat JBoss Enterprise Application Platform 7.4 on RHEL 7eap7-undertow-0:2.2.33-1.SP1_redhat_00001.1.el7eapRHSA-2024:5143
Red Hat JBoss Enterprise Application Platform 8undertow-coreRHSA-2024:4392

Frequently Asked Questions

A vulnerability was found in Undertow, where the chunked response hangs after the body was flushed. The response headers and body were sent but the client would continue waiting as Undertow does not send the expected 0\r\n termination of the chunked response. This results in uncontrolled resource consumption, leaving the server side to a denial of service attack. This happens only with Java 17 TLSv1.3 scenarios.
O3 Security · Impact-Aware SCA

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CVE-2024-5971: undertow-core DoS — Fixed in 2.3.15.Final