Answer in brief
CVE-2026-46340 records a High severity (CVSS 7.5) vulnerability in Netty: SCTP reassembly nests buffers without bound. The current sources do not mark it as known exploited. The current feed maps netty/netty (generic), io.netty:netty-transport-sctp (maven), io.netty:netty-transport-sctp (maven), io.netty:netty-transport-sctp (maven) and additional mapped packages. 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 7.5. 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), io.netty:netty-transport-sctp (maven), io.netty:netty-transport-sctp (maven), io.netty:netty-transport-sctp (maven) and additional mapped packages. Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:a:netty:netty:*:*:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| netty/nettygeneric | >= 4.2.0.Final, < 4.2.15.Final || < 4.1.135.Final | Not reported |
| io.netty:netty-transport-sctpmaven | >=4.2.0.Final,<=4.2.14.Final | 4.2.15.Final |
| io.netty:netty-transport-sctpmaven | <=4.1.134.Final | 4.1.135.Final |
| io.netty:netty-transport-sctpmaven | >=4.2.0.Final <4.2.15.Final | 4.2.15.Final |
| io.netty:netty-transport-sctpmaven | >=0 <4.1.135.Final | 4.1.135.Final |
Published upstream
Jun 12, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 10, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jun 11, 2026
Netty is a network application framework for development of protocol servers and clients. In versions of netty-transport-sctp prior to 4.1.135.Final and 4.2.15.Final, for each non-complete SctpMessage fragment the handler does `fragments.put(streamId, Unpooled.wrappedBuffer(frag, byteBuf))`, wrapping the previous accumulator and the new slice into a *new* CompositeByteBuf every time. After N fragments the accumulator is an N-deep chain of composites, each holding references and component arrays; readableBytes()/getBytes() on the final buffer recurse N levels. There is no limit on N, on total bytes, or on the number of streamIdentifiers an attacker can open (each gets its own map entry). A peer that never sets the `complete` flag can grow this structure indefinitely from tiny 1-byte DATA chunks. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Quoted source text, attributed separately from HOL analysis.