Answer in brief
CVE-2026-44249 records a High severity (CVSS 8.1) vulnerability in Netty has an IPv6 Subnet Filter Bypass via Incorrect Comparator Masking. The current sources do not mark it as known exploited. The current feed maps netty/netty (generic), io.netty:netty-handler (maven), io.netty:netty-handler (maven), io.netty:netty-handler (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 8.1. 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-handler (maven), io.netty:netty-handler (maven), io.netty:netty-handler (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-handlermaven | >=4.2.0.Final,<=4.2.14.Final | 4.2.15.Final |
| io.netty:netty-handlermaven | <=4.1.134.Final | 4.1.135.Final |
| io.netty:netty-handlermaven | >=4.2.0.Final <4.2.15.Final | 4.2.15.Final |
| io.netty:netty-handlermaven | >=0 <4.1.135.Final | 4.1.135.Final |
Published upstream
Jun 11, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Sep 11, 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 netty-handler prior to versions 4.1.135.Final and 4.2.15.Final, an attacker can bypass IPv6 subnet rules due to an incorrect masking operation in IpSubnetFilterRule.compareTo(). Valid public IP addresses can bypass the restrictions. Versions 4.1.135.Final and 4.2.15.Final patch the issue.
Quoted source text, attributed separately from HOL analysis.