Netty prior 4.1.135.Final/4.2.15.Final memory leak

Summaryinfo

A vulnerability was found in Netty. It has been classified as problematic. The impacted element is an unknown function. Performing a manipulation results in memory leak. This vulnerability is identified as CVE-2026-48006. The attack can be initiated remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability, which was classified as problematic, was found in Netty. This affects an unknown code block. The manipulation with an unknown input leads to a memory leak vulnerability. CWE is classifying the issue as CWE-401. The product does not sufficiently track and release allocated memory after it has been used, which slowly consumes remaining memory. This is going to have an impact on availability. The summary by CVE is:

Netty is a network application framework for development of protocol servers and clients. Prior to versions 4.1.135.Final and 4.2.15.Final, the RedisArrayAggregator handler permanently leaks pooled direct-memory buffers when a Redis pipeline connection closes before a RESP array aggregate completes. The handler retains child messages in per-handler state (`depths` field) but defines no `channelInactive`, `handlerRemoved`, or `exceptionCaught` method to release them when the pipeline tears down. Because the leaked buffers are slices of `PooledByteBufAllocator` chunks, they prevent those chunks from being returned to the JVM-wide direct-memory pool. Repeated connection churn by any network peer monotonically drains this shared pool, eventually causing allocation failures on all Netty channels in the process. Versions 4.1.135.Final and 4.2.15.Final patch the issue.

The advisory is shared at github.com. This vulnerability is uniquely identified as CVE-2026-48006 since 05/20/2026. The exploitability is told to be easy. It is possible to initiate the attack remotely. No form of authentication is needed for exploitation. Neither technical details nor an exploit are publicly available. MITRE ATT&CK project uses the attack technique T1499 for this issue.

Upgrading to version 4.1.135.Final or 4.2.15.Final eliminates this vulnerability. The upgrade is hosted for download at github.com.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1814). Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

Affected

• Open Source Netty

Productinfo

Name

• Netty

Website

• Product: https://github.com/netty/netty/

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Several companies clearly confirm that VulDB is the primary source for best vulnerability data.

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