What is CVE-2026-42583?

CVE-2026-42583 is a high-severity vulnerability in Io.netty Netty-codec, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-05-13.

How severe is CVE-2026-42583?

High severity. CVSS v3 base score is 7.5 out of 10.

Resource exhaustion in Io.netty Netty-codec

CVE-2026-42583

Netty is an asynchronous, event-driven network application framework. Prior to 4.2.13.Final and 4.1.133.Final, Lz4FrameDecoder allocates a ByteBuf of size decompressedLength (up to 32 MB per block) before LZ4 runs. A peer only needs a 21-b…

Vulnerability class: DoS (Denial of Service)

EPSS: 0.000 (4.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.5 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.

Affected products

Io.netty Netty-codec — versions < 4.1.133.Final
Io.netty Netty-codec-compression — versions < 4.2.13.Final
Netty — versions >= 4.2.0.Alpha1, < 4.2.13.Final, < 4.1.133.Final

Weakness classification (CWE)

References

security-advisories@github.com (x_refsource_CONFIRM, Exploit, Vendor Advisory)

Frequently asked questions

What is CVE-2026-42583?: CVE-2026-42583 is a high-severity vulnerability in Io.netty Netty-codec, classified under Uncontrolled Resource Consumption. CVSS score: 7.5/10. Published 2026-05-13.
How severe is CVE-2026-42583?: High severity. CVSS v3 base score is 7.5 out of 10.