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Vulnerability · Published Aug 18, 2026 · Assigned by GitHub_M

CVE-2026-59949yawkat LZ4 Java: JVM Crash via Null Byte Array in lz4-java Streaming XXHash JNI (StreamingXXHash32JNI / StreamingXXHash64JNI)

Medium 6.5

In plain English

A medium-severity null pointer dereference in lz4-java from yawkat. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.5% (higher than 41% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)6.5Medium
Exploit odds (30 days)0.5%top 59.5% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official description

yawkat LZ4 Java provides LZ4 compression for Java. Prior to 1.11.1, JNI-backed XXHash implementations fail to validate the byte array object and the off and len arguments in XXHashFactory.nativeInstance().hash32().hash(), XXHashFactory.nativeInstance().hash64().hash(), XXHashFactory.nativeInstance().newStreamingHash32().update(), and XXHashFactory.nativeInstance().newStreamingHash64().update(), allowing null arrays or oversized ranges to reach native code, read outside the Java array, and fatally terminate the JVM. This issue is fixed in version 1.11.1.

Affected packages & fixed versions

EcosystemPackageFixed inAdvisory
Debian:12lz4-javano fix listedDEBIAN-CVE-2026-59949
Debian:13lz4-javano fix listedDEBIAN-CVE-2026-59949
Debian:14lz4-java1.11.2+ds1-1DEBIAN-CVE-2026-59949
Mavenat.yawk.lz4:lz4-java1.11.1GHSA-xx22-p4ch-683r
Mavenorg.lz4:lz4-javano fix listedGHSA-xx22-p4ch-683r
Ubuntu:22.04:LTSlz4-javano fix listedUBUNTU-CVE-2026-59949
Ubuntu:24.04:LTSlz4-javano fix listedUBUNTU-CVE-2026-59949
Ubuntu:26.04:LTSlz4-javano fix listedUBUNTU-CVE-2026-59949
Ubuntu:26.10lz4-javano fix listedUBUNTU-CVE-2026-59949

Affected products (as reported)

VendorProductVersions
yawkat lz4-java < 1.11.1

Weakness: CWE-476 · Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H

References