CVE-2026-56817

criticalpriority · track · 39EPSS 0.007 · 52 %ileDEEUUS

grimoire priorityP2 · Scheduled

Exploitable?

—

no known exploitation

Likely / severe?

0.69% (52nd) EPSS

CVSS 9.8 · critical

Is it mine?

16 products

Check your exposure

Who says so?

5 sources

cnnvd · enisa_euvd · cert_bund · nvd

EPSS · scored 2026-10-22

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

Technical severity, 0–10. One row per scoring source.

9.8

010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–critical · 4.8–9.8

v3.19.8criticalCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 3.9 · impact 5.9

v4.08.3highCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:Nsecondary · ENISA EU

v4.08.3highCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · security-advisories@github.com

v4.04.8mediumCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:Xsecondary · CVSS-BT (t0sche)

ssvc

A stakeholder decision — act, attend, or track — from exploitation and impact.

Exploitation: none · Automatable: yes · Technical Impact: partialcoordinatorcisa_ssvcUS

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-611USCWE-611US

affected products (16)

Products and version ranges known to be affected.

IBM App Connect Enterprise for Manufactoringall versionscert_bundDEcpe:/a:ibm:app_connect_enterprise:for_manufactoring
IBM DB2all versionscert_bundDEcpe:/a:ibm:db2:-
IBM SPSS Analytic Serverall versionscert_bundDEcpe:/a:ibm:spss:analytic_server
IBM SPSS Modeler 19.0.0.0all versionscert_bundDEcpe:/a:ibm:spss:modeler_19.0.0.0
Red Hat Enterprise Linuxall versionscert_bundDEcpe:/o:redhat:enterprise_linux:-
SUSE Linuxall versionscert_bundDEcpe:/o:suse:suse_linux:-
Open Source Netty< 4.1.136cert_bundDE
Open Source Netty< 4.2.16cert_bundDE
Open Source Open Source Netty <4.1.136< 4.1.136cert_bundDE
Open Source Open Source Netty <4.2.16< 4.2.16cert_bundDE
netty netty4.1.0.Final, → 4.1.136.Finalenisa_euvdEU
netty netty4.2.0.Final, → 4.2.16.Finalenisa_euvdEU
netty netty4.1.0 → 4.1.136nvdUScpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
netty netty4.2.0 → 4.2.16nvdUScpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*
Maven io.netty:netty-codec-xml4.1.0.Final → 4.1.136.FinalosvUSpkg:maven/io.netty/netty-codec-xml
Maven io.netty:netty-codec-xml4.2.0.Final → 4.2.16.FinalosvUSpkg:maven/io.netty/netty-codec-xml

advisories (2)

Vendor and ecosystem advisories describing this.

WID-SEC-W-2026-2356Netty: Mehrere SchwachstellenDeutsch2026-07-14csaf · cert_bundDE
Ein Angreifer kann mehrere Schwachstellen in Netty ausnutzen, um Sicherheitsprüfungen zu umgehen, Anfragen oder Header zu manipulieren, Zertifikatsprüfungen zu unterlaufen sowie einen Denial of Service zu verursachen.
GHSA-4qhr-g3c6-fcfxNetty XML: Injection / Risky Sink — unconfigured XML factory with active DTD and entity handling2026-07-22ghsa · osvUS
Any caller that can deliver bytes to a Netty channel pipeline containing `XmlDecoder` can send XML with a DOCTYPE declaration to a parser instantiated with no security configuration — but whether external entities are actually resolved depends on Aalto XML's async parser behavior, making this a confirmed misconfiguration with conditional exploitability.

also known as (3)

Other names and identifiers for this entity.

sources

Which sources assert this record, and when.

cnnvd enisa_euvd cert_bund nvd osv NVD CVE.org MITRE

published 2026-07-21modified 2026-07-30

references (16)

External citations — patches, advisories, analysis.

scry

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