CVE-2026-48006
HighCVSS 7.5Exploitation Probability (EPSS)
Low risk39th percentile - higher than 39% of all known CVEs
Summary
A vulnerability in the Netty library causes permanent leakage of pooled direct-memory buffers in the RedisArrayAggregator handler when a Redis pipeline connection closes before RESP array aggregation completes. The leaked buffers prevent memory chunks from being returned to the JVM-wide direct-memory pool, leading to exhaustion. The issue is fixed in versions 4.1.135.Final and 4.2.15.Final.
Risk Assessment
The risk is that any network peer can exhaust the JVM direct-memory pool by repeatedly closing Redis pipeline connections, causing a denial of service (DoS) for all Netty channels in the process. This can lead to allocation failures and application unavailability.
Recommendation
Immediately update Netty to version 4.1.135.Final or 4.2.15.Final (or later). If an update is not possible, consider restricting access to Redis services and monitoring JVM direct-memory usage.
Original NVD description (English source)
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.