CVSS 3.1
7.5 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:HCVE-2026-56819
High (7.5) in netty netty. EPSS 0.7% chance of exploitation in the next 30 days. Fixed in io.netty:netty-codec-http2 4.1.136.Final, 4.2.16.Final.
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.
Severity
- EPSS
- 0.7% chance of exploitation in the next 30 days; higher than 51% of CVEs (scores of 2026-10-31)
- CWEs
- CWE-400, CWE-401
- Published
- Modified
- Record from
- the NVD, synced
Affected
- netty:netty
Packages (OSV)
| Advisory | Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|---|
| GHSA-93wv-jw9v-4972 | 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 |
References
- 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
- https://github.com/netty/netty/security/advisories/GHSA-93wv-jw9v-4972