NULL Pointer Dereference Affecting at.yawk.lz4:lz4-java package, versions [,1.11.1)
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-ATYAWKLZ4-18313068
- published26 Jul 2026
- disclosed24 Jul 2026
- creditMichał Majchrowicz
Introduced: 24 Jul 2026
CVE-2026-59949 (opens in a new tab)How to fix?
Upgrade at.yawk.lz4:lz4-java to version 1.11.1 or higher.
Overview
Affected versions of this package are vulnerable to NULL Pointer Dereference and out-of-bounds read in the native XXHash implementations reached through XXHashFactory.nativeInstance(), where SafeUtils.checkRange() skips all array validation when len == 0 and lets invalid references or ranges reach the JNI code. An attacker can crash the JVM, and expose in-process memory before the crash, by passing a null array with zero length or an oversized length to the native hash32(), hash64(), or streaming update() methods, which then read outside the array bounds in native code. Exploitation requires the application to let the attacker influence the array reference or the offset and length arguments to a native XXHash call, not merely the contents of a valid array, and only the native JNI instances are affected.
Workaround
This vulnerability can be avoided by using XXHashFactory.safeInstance() instead of nativeInstance(), which computes the hash in pure Java and never crosses the JNI boundary where the flaw occurs.