Is CVE-2026-42587 actively exploited?

No active exploitation of CVE-2026-42587 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-42587 be exploited remotely?

Yes. CVE-2026-42587 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-42587?

CVE-2026-42587 has a CVSS score of 7.5 (HIGH).

HOME VULNERABILITIESCVE-2026-42587

HIGH

CVE-2026-42587

CWE-400Published: May 13, 2026· Updated: May 18, 2026

7.5

CVSS v3.1

EPSS:0.04%probability of exploitation in 30 daysPercentile:12.1th

Official Description

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, HttpContentDecompressor accepts a maxAllocation parameter to limit decompression buffer size and prevent decompression bomb attacks. This limit is correctly enforced for gzip and deflate encodings via ZlibDecoder, but is silently ignored when the content encoding is br (Brotli), zstd, or snappy. An attacker can bypass the configured decompression limit by sending a compressed payload with Content-Encoding: br instead of Content-Encoding: gzip, causing unbounded memory allocation and out-of-memory denial of service. The same vulnerability exists in DelegatingDecompressorFrameListener for HTTP/2 connections. This vulnerability is fixed in 4.2.13.Final and 4.1.133.Final.

NVD Source

Technical Analysis

CVE-2026-42587 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.

A successful exploit results in availability disruption (denial of service), with a CVSS base score of 7.5.