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Fencer Vulns
high 7.5

CVE-2026-73507 json

Netty: Denial of Service in XmlFrameDecoder via CPU Exhaustion

published 2026-07-24 3 mo ago modified 2026-09-23 46 d ago also GHSA-v74w-7mr3-4qg3 , EUVD-2026-58083

cvss
7.5
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.8%
EPSS 0.8% chance of exploitation in 30 days, percentile 56%
public exploits
0
none known

Summary

Netty is an asynchronous, event-driven network application framework. Prior to 4.1.136.Final and 4.2.16.Final, io.netty.handler.codec.xml.XmlFrameDecoder.decode() failed to preserve closing-tag parser state across invocations, so an unauthenticated remote attacker could trickle-feed repeated </ sequences that repeatedly rescanned the accumulated buffer and exhausted an EventLoop thread's CPU, causing denial of service with a maxFrameLength of 1 MB. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

Patch / fix

  • maven io.netty:netty-codec-xml 4.1.136.Final, 4.2.16.Final
  • netty netty 4.1.136, 4.2.16

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-73507 updated cvss 7.5

io.netty/netty-codec-xml: Netty: Denial of Service via CPU Exhaustion in XmlFrameDecoder

  • Red Hat Single Sign-On 7 netty-codec-xml 4.1.119.Final-redhat-00004
    affected: workaround, no fix planned “Will not fix”
  • Red Hat build of Apache Camel 4.18.4 for Spring Boot 3.5.16
    fixed: vendor fix RHSA-2026:71675
  • Red Hat JBoss Enterprise Application Platform 7 netty-codec-xml 4.1.119.Final-redhat-00004, jboss-eap-7/eap74-els-openjdk8-openshift-rhel8, jboss-eap-7/eap74-els-openjdk11-openshift-rhel8, jboss-eap-7/eap74-els-openjdk17-openshift-rhel8
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
yes
Technical impact
partial
Assessed
2 mo ago

Exploit prediction

0.79% chance of exploitation in the next 30 days, higher than 56% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
GitHub 3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Affected packages

ecosystem package affected fixed in
maven io.netty:netty-codec-xml
>=4.2.0.Final, <4.2.16.Final
<4.1.136.Final
4.2.16.Final
4.1.136.Final

Affected products

  • netty netty

Classification

Weakness
  • CWE-400 Uncontrolled Resource Consumption

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.