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, a remote unauthenticated peer can leak one direct `ByteBuf` per HTTP/2 `DATA` frame in applications that enable HTTP/2 content decompression via `DelegatingDecompressorFrameListener`. When a `DATA` frame is processed for a stream whose decompressor has already been closed, `Http2Decompressor.decompress(...)` calls `decompressor.writeInbound(data.retain())` and does not release the retained buffer on the error path, eventually exhausting direct memory and crashing the JVM. This issue is fixed in versions 4.1.136.Final and 4.2.16.Final.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| netty | netty | >= 4.2.0.Final, < 4.2.16.Final, >= 4.1.0.Final, < 4.1.136.Final | — |
Fixed in Linux distributions
Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.
Debian
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian 14 | netty | No fix yet | — |
| Debian 13 | netty | No fix yet | — |
| Debian 12 | netty | No fix yet | — |
Ubuntu
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu 26.10 | netty | No fix yet | — |
Show 7 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu Pro 26.04 LTS | netty | No fix yet | — |
| Ubuntu Pro 24.04 LTS | netty | No fix yet | — |
| Ubuntu Pro 22.04 LTS | netty | No fix yet | — |
| Ubuntu Pro 20.04 LTS | netty | No fix yet | — |
| Ubuntu Pro 18.04 LTS | netty | No fix yet | — |
| Ubuntu Pro 16.04 LTS | netty | No fix yet | — |
| Ubuntu Pro 14.04 LTS | netty | No fix yet | — |
SUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES 15 SP7 | netty | 4.1.136-150200.4.53.1 | SUSE-SU-2026:3482-1 |
| SLES 15 SP7 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
| SLES 15 SP6 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
| SLES 15 SP5 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
| SLES 15 SP4 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
Show 5 more (older releases, extended support, other products)Fewer releases
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| SLES for SAP 15 SP6 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
| SLES for SAP 15 SP5 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
| SLES for SAP 15 SP4 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
| SLE HPC 15 SP5 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
| SLE HPC 15 SP4 | netty-tcnative | 2.0.80-150200.3.48.1 | SUSE-SU-2026:3482-1 |
openSUSE
Security tracker ↗| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| openSUSE Tumbleweed | netty | 4.1.136-1.1 | openSUSE-SU-2026:11394-1 |
Wolfi
| Release | Package | Fixed in | Advisory |
|---|---|---|---|
| Wolfi rolling | celeborn-0.6 | 0.6.3-r13 | — |
| Wolfi rolling | druid | 37.0.0-r46 | — |
| Wolfi rolling | keycloak-26.5 +2 | No fix yet | — |
| Wolfi rolling | keycloak-26.6 +2 | 26.6.4-r21 | — |
| Wolfi rolling | kserve-modelmesh | 0.12.0-r38 | — |
| Wolfi rolling | neo4j-2026.01 | 2026.01.4-r6 | — |
| Wolfi rolling | opensearch-3-discovery-ec2 +2 | 3.8.0-r3 | — |
| Wolfi rolling | opensearch-3-security-analytics | 3.8.0-r2 | — |
| Wolfi rolling | sonarqube | 26.9.0.129388-r4 | — |
| Wolfi rolling | spark-4.0-scala-2.13 | 4.0.4-r1 | — |
| Wolfi rolling | spark-4.1-scala-2.13 | 4.1.3-r2 | — |
| Wolfi rolling | trino-plugin-opensearch | 483-r7 | — |
| Wolfi rolling | zipkin +1 | 3.6.1-r19 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
GitHub 1 repository
-
xiaoqiMikko/netty-http2-check ★ 0 · Sep 5, 2026
CVE-2025-55163 / CVE-2026-56819: offline checker for the 7 netty-codec-http2 CVEs. Tells you which ones you are exposed to, and the one version that fixes all seven (4.1.136.Final / 4.2.16.Final) - w…
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
Affected packages
| Ecosystem | Package | Affected | Fixed | Record |
|---|---|---|---|---|
| Maven | io.netty:netty-codec-http2 | >= 4.2.0, < 4.2.16.Final | 4.2.16.Final | GHSA-93wv-jw9v-4972 |
| Maven | io.netty:netty-codec-http2 | >= 4.1.0.Final, < 4.1.136.Final | 4.1.136.Final | GHSA-93wv-jw9v-4972 |
Advisories 6
- WID-SEC-2026-3376 Atlassian Bamboo, Bitbucket, Confluence, Fisheye/Crucible, Jira Software und Jira Service Management: Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 10, 2026
- WID-SEC-2026-2923 Atlassian Produkte (Bamboo, Bitbucket, Confluence, Crucible, Fisheye, und Jira): Mehrere Schwachstellen BSI CERT-Bund (WID) · Nov 8, 2026
- WID-SEC-2026-2356 Netty: Mehrere Schwachstellen BSI CERT-Bund (WID) · Oct 25, 2026
- NCSC-2026-0325 Kwetsbaarheden verholpen in Atlassian producten NCSC-NL (Netherlands) · Aug 24, 2026
- SUSE-SU-2026:3482-1 Security update for netty, netty-tcnative SUSE / openSUSE Security Updates · Aug 5, 2026
- openSUSE-SU-2026:11394-1 netty-4.1.136-1.1 on GA media SUSE / openSUSE Security Updates · Jul 29, 2026
References
- https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972
- https://github.com/netty/netty/commit/5b68c61f37aa4a3045cba624cbea239655c9003b
- https://github.com/netty/netty/commit/bb2ff68a1fb71cb4b0eb9a9e17b66c52aff680c6
- https://github.com/netty/netty/releases/tag/netty-4.1.136.Final
- https://github.com/netty/netty/releases/tag/netty-4.2.16.Final