Critical severity9.8OSV Advisory· Published Jul 21, 2026· Updated Jul 30, 2026
CVE-2026-56817
CVE-2026-56817
Description
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.
AI Insight
LLM-synthesized narrative grounded in this CVE's description and references.
Affected packages
Versions sourced from the GitHub Security Advisory.
| Package | Affected versions | Patched versions |
|---|---|---|
io.netty:netty-codec-xmlMaven | >= 4.2.0.Final, < 4.2.16.Final | 4.2.16.Final |
io.netty:netty-codec-xmlMaven | >= 4.1.0.Final, < 4.1.136.Final | 4.1.136.Final |
Affected products
21netty-4.1.135.Final, netty-4.2.15.Final, netty-4.1.134.Final, …+ 2 more
- (no CPE)range: netty-4.1.135.Final, netty-4.2.15.Final, netty-4.1.134.Final, …
- cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:*range: >=4.1.0,<4.1.136
- (no CPE)range: 4.2.0.Final - 4.2.15.Final, 4.1.0.Final - 4.1.135.Final
- osv-coords18 versionspkg:apk/chainguard/apache-hoppkg:apk/chainguard/apache-hop-fipspkg:apk/chainguard/celeborn-0.5pkg:apk/chainguard/celeborn-0.6pkg:apk/chainguard/gremlin-serverpkg:apk/chainguard/management-api-for-apache-cassandra-5.0pkg:apk/chainguard/pinotpkg:apk/chainguard/pinot-fipspkg:apk/chainguard/seata-serverpkg:apk/chainguard/tezpkg:apk/chainguard/thingsboard-tb-mqtt-transportpkg:apk/chainguard/thingsboard-tb-nodepkg:apk/wolfi/celeborn-0.6pkg:apk/wolfi/management-api-for-apache-cassandra-5.0pkg:apk/wolfi/tezpkg:apk/wolfi/thingsboard-tb-mqtt-transportpkg:apk/wolfi/thingsboard-tb-nodepkg:rpm/opensuse/netty&distro=openSUSE%20Tumbleweed
< 2.18.1-r8+ 17 more
- (no CPE)range: < 2.18.1-r8
- (no CPE)range: < 2.18.1-r6
- (no CPE)range: < 0.5.4-r30
- (no CPE)range: < 0.6.3-r11
- (no CPE)range: < 3.8.1-r2
- (no CPE)range: < 0.1.122-r2
- (no CPE)range: < 1.5.1-r4
- (no CPE)range: < 1.5.1-r4
- (no CPE)range: < 2.6.0-r21
- (no CPE)range: < 0.10.5-r23
- (no CPE)range: < 4.3.1.3-r7
- (no CPE)range: < 4.3.1.3-r7
- (no CPE)range: < 0.6.3-r11
- (no CPE)range: < 0.1.122-r2
- (no CPE)range: < 0.10.5-r23
- (no CPE)range: < 4.3.1.3-r7
- (no CPE)range: < 4.3.1.3-r7
- (no CPE)range: < 4.1.136-1.1
Patches
Vulnerability mechanics
References
7- github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003bnvdPatchWEB
- github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6nvdPatchWEB
- github.com/advisories/GHSA-4qhr-g3c6-fcfxghsaADVISORY
- github.com/netty/netty/security/advisories/GHSA-4qhr-g3c6-fcfxnvdVendor AdvisoryWEB
- nvd.nist.gov/vuln/detail/CVE-2026-56817ghsaADVISORY
- github.com/netty/netty/releases/tag/netty-4.1.136.FinalnvdRelease NotesWEB
- github.com/netty/netty/releases/tag/netty-4.2.16.FinalnvdRelease NotesWEB
News mentions
1- Netty: Seven Vulnerabilities Disclosed Together Affecting Protocol Handling and Data ParsingVypr Intelligence · Jul 23, 2026