Answer in brief
CVE-2026-100655 records a Medium severity (CVSS 6.9) vulnerability in Netty before 4.1.138.Final Denial of Service via SpdySessionHandler. The current sources do not mark it as known exploited. The current feed maps netty/netty (generic), netty/netty (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.9. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps netty/netty (generic), netty/netty (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| netty/nettygeneric | >=0 <4.1.138.Final | 4.1.138.Final |
| netty/nettygeneric | >=4.2.0.Final <4.2.18.Final | 4.2.18.Final |
Published upstream
Sep 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 26, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Sep 26, 2026
Netty (io.netty:netty-codec-http) versions up to and including 4.1.137.Final and from 4.2.0.Final through 4.2.17.Final accept an unlimited number of concurrent remote-initiated SPDY streams: SpdySessionHandler defaults localConcurrentStreams to Integer.MAX_VALUE and exposes no API to change it. A remote peer that opens a SPDY connection and sends millions of SYN_STREAM frames with FLAG_FIN=0 causes the server to allocate unbounded heap and direct memory, eventually triggering a JVM OutOfMemoryError and crashing the service. Fixed in 4.1.138.Final and 4.2.18.Final.
Quoted source text, attributed separately from HOL analysis.