High severity · published Aug 13, 2026
CVE-2026-73507
Netty: Denial of Service in XmlFrameDecoder via CPU Exhaustion
7.5
CVSS
0.8%
EPSS
No
On KEV
Description
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.8% · higher than 56% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NE
netty · netty
< 4.1.136.Final; >= 4.2.0.Final, < 4.2.16.Final · source: vendor, NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-73507
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-73507
Patch
https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
Patch
https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
Release Notes
https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
Release Notes
https://github.com/netty/netty/releases/tag/netty-4.2.16.Final
Vendor Advisory
https://github.com/netty/netty/security/advisories/GHSA-v74w-7mr3-4qg3
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