Answer in brief
CVE-2026-42584 records a High severity (CVSS 7.3) vulnerability in Netty: HttpClientCodec response desynchronization. The current sources do not mark it as known exploited. The current feed maps netty/netty (generic), io.netty/netty-codec-http (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-42584 records a High severity (CVSS 7.3) vulnerability in Netty: HttpClientCodec response desynchronization. The current sources do not mark it as known exploited. The current feed maps netty/netty (generic), io.netty/netty-codec-http (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 7.3. 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-codec-http (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| netty/nettygeneric | >= 4.2.0.Alpha1, < 4.2.13.Final || < 4.1.133.Final | Not reported |
| io.netty/netty-codec-httpgeneric | >= 4.2.0.Alpha1, < 4.2.13.Final || < 4.1.133.Final | Not reported |
Published upstream
May 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 9, 2026
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Quoted source text, attributed separately from HOL analysis.
CVSS is 7.3. 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-codec-http (generic). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| netty/nettygeneric | >= 4.2.0.Alpha1, < 4.2.13.Final || < 4.1.133.Final | Not reported |
| io.netty/netty-codec-httpgeneric | >= 4.2.0.Alpha1, < 4.2.13.Final || < 4.1.133.Final | Not reported |
Published upstream
May 13, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Jul 21, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Jul 9, 2026
Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpClientCodec pairs each inbound response with an outbound request by queue.poll() once per response, including for 1xx. If the client pipelines GET then HEAD and the server sends 103, then 200 with GET body, then 200 for HEAD, the queue pairs HEAD with the first 200. The HEAD rule then skips reading that message’s body, so the GET entity bytes stay on the stream and the following 200 is parsed from the wrong offset. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.
Quoted source text, attributed separately from HOL analysis.