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Critical 9.8Published Jul 21, 2026

CVE-2026-56817Netty is a network application framework for development of protocol servers and clients.

Updated under an hour ago ()

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It affects netty. Add what you run to find out whether that includes you.

No exploitation reported and no EPSS estimate yet.

Netty is a network application framework for development of protocol servers and clients. In versions 4.2.0.Final through 4.2.15.Final and 4.1.0.Final through 4.1.135.Final, any caller that can deliver bytes to a Netty channel pipeline containing `XmlDecoder` can send XML with a `DOCTYPE` declaration to an `AsyncXMLInputFactory` instantiated with no security configuration, leaving DTD and entity handling active depending on Aalto XML async parser behavior and creating conditional XML external entity risk. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.

CVSS
9.8 CRITICAL (v3.1, NVD)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Weakness (CWE)
CWE-611
Known exploited
Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days)
Not loaded for this CVE
Assigned by
Not given
NVD analysis
Analyzed
Record last updated
Jul 30, 2026
First seen by InfoSec Signals
Oct 9, 2026

Affected products

Affected products
netty netty
netty:netty
from 4.1.0 before 4.1.136; from 4.2.0 before 4.2.16
NVD

References

  • patch
  • patch
  • release-notes
  • release-notes
  • vendor-advisory

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.

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