Answer in brief
CVE-2026-59949 records a Medium severity (CVSS 6.5) vulnerability in yawkat LZ4 Java: JVM Crash via Null Byte Array in lz4-java Streaming XXHash JNI (StreamingXXHash32JNI / StreamingXXHash64JNI). The current sources do not mark it as known exploited. The current feed maps yawkat/lz4-java (generic), at.yawk.lz4:lz4-java (maven), org.lz4:lz4-java (maven). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
Answer in brief
CVE-2026-59949 records a Medium severity (CVSS 6.5) vulnerability in yawkat LZ4 Java: JVM Crash via Null Byte Array in lz4-java Streaming XXHash JNI (StreamingXXHash32JNI / StreamingXXHash64JNI). The current sources do not mark it as known exploited. The current feed maps yawkat/lz4-java (generic), at.yawk.lz4:lz4-java (maven), org.lz4:lz4-java (maven). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps yawkat/lz4-java (generic), at.yawk.lz4:lz4-java (maven), org.lz4:lz4-java (maven). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| yawkat/lz4-javageneric | < 1.11.1 | Not reported |
| at.yawk.lz4:lz4-javamaven | >=0 <1.11.1 | 1.11.1 |
| org.lz4:lz4-javamaven | >=0 | Not reported |
Published upstream
Aug 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 8, 2026
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.
Quoted source text, attributed separately from HOL analysis.
CVSS is 6.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps yawkat/lz4-java (generic), at.yawk.lz4:lz4-java (maven), org.lz4:lz4-java (maven). Check affected ranges and fixed versions before updating.
| Package | Affected range | Fixed version |
|---|---|---|
| yawkat/lz4-javageneric | < 1.11.1 | Not reported |
| at.yawk.lz4:lz4-javamaven | >=0 <1.11.1 | 1.11.1 |
| org.lz4:lz4-javamaven | >=0 | Not reported |
Published upstream
Aug 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Aug 18, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Aug 8, 2026
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.
Quoted source text, attributed separately from HOL analysis.