LZ4 Java: Native XXHash implementations can crash the JVM when passed invalid byte array ranges

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

6.5 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H

EPSS

• CVE-2026-59949: 0.47% estimated exploitation activity in the next 30 days; percentile 40.40 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

Summary Insufficient validation of byte array arguments in JNI-based XXHash implementations in lz4-java 1.11.0 and earlier allows callers to crash the JVM by passing an invalid array reference or invalid range to native XXHash methods. This affects applications where an attacker can influence the byte array object or the off / len arguments passed to affected XXHash APIs. It does not affect the common case where only the contents of a valid byte array are attacker-controlled. Java-based XXHash implementations are not affected. Details The JNI-backed XXHash implementations pass caller-provided byte array arguments to native code. The affected APIs are: - XXHashFactory.nativeInstance().hash32().hash(byte[] buf, int off, int len, int seed) - XXHashFactory.nativeInstance().hash64().hash(byte[] buf, int off, int len, long seed) - XXHashFactory.nativeInstance().newStreamingHash32(seed).update(byte[] bytes, int off, int len) -…

Published by the source

24 Jul 2026, 16:13 UTC

Last modified by the source

24 Jul 2026, 16:13 UTC

Source last checked

26 Oct 2026, 16:54 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-xx22-p4ch-683r

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# Patch Next advisory brief: CVE-2026-59949

Advisory: LZ4 Java: Native XXHash implementations can crash the JVM when passed invalid byte array ranges
IDs: CVE-2026-59949, GHSA-xx22-p4ch-683r
Record: https://patchnext.com/advisories/cve-2026-59949 (revision 1, source checked 26 Oct 2026, 16:54 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: Medium (CVSS 6.5)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Partial vendor fix; fixed versions by package: at.yawk.lz4:lz4-java 1.11.1. A vendor fix does not mean a deployment is fixed.

## Affected components
- Maven at.yawk.lz4:lz4-java: affected <= 1.11.0; fixed in 1.11.1
- Maven org.lz4:lz4-java: affected <= 1.8.1

## Suggested inspection (read-only)
- Maven at.yawk.lz4:lz4-java: check the installed version with your package manager.
- Maven org.lz4:lz4-java: check the installed version with your package manager.

## Supported action
No complete vendor fix is recorded. Follow the primary source's mitigation guidance and check this record again before closing anything.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on at.yawk.lz4:lz4-java, org.lz4:lz4-java.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-xx22-p4ch-683r (GitHub-reviewed advisory GHSA-xx22-p4ch-683r lists affected ranges: Maven at.yawk.lz4:lz4-java >=0 =0 <=1.8.1)

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