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CVE-2026-106453 · GHSA-6cx8-rjf8-pr8g

yawkat LZ4 Java: LZ4DecompressorWithLength allocates the unvalidated size from the 4-byte length header, so a 5-byte input triggers a 1 GiB allocation and OutOfMemoryError

Risk score
43/100
CVSS
5.3 v3.1
Exploit chance (30 days)
0.4%
Published
6 Oct 2026

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What to know

What it is
yawkat LZ4 Java provides LZ4 compression for Java. Prior to 1.11.2, LZ4DecompressorWithLength uses getDecompressedLength to trust the four-byte decompressed-length header before validating the compressed input, allowing a five-byte attacker-supplied input whose header declares a large output size to request up to appr…
Affected
at.yawk.lz4:lz4-java (maven) <= 1.11.1; org.lz4:lz4-java (maven) <= 1.8.1
Fix
Upgrade at.yawk.lz4:lz4-java to 1.11.2 or later.
Exploitation
No known exploitation

Story map

Story map: at.yawk.lz4:lz4-javaTHE FLAWSTHE FIXCVE-2026-106453Yawkat LZ4 Java:LZ4DecompressorWithLengthallocates the unvalidated size…CVSS 5.3 · EPSS 0%CVE-2026-106451Yawkat LZ4 Java: Nativelibrary extraction to a sharedtemporary directory is…CVSS 7.3 · EPSS 0%CVE-2026-106450Yawkat LZ4 Java:LZ4FrameInputStreamreallocates block buffers for…CVSS 5.3 · EPSS 0%CVE-2026-106452Yawkat LZ4 Java:LZ4BlockInputStreamallocates an unvalidated…CVSS 5.3 · EPSS 0%Upgrade at.yawk.lz4:lz4-java1.11.2 · 1.11.4or later on your release lineWho is exposedat.yawk.lz4:lz4-java (maven)<= 1.11.3; org.lz4:lz4-java(maven) >= 1.7.0, <= 1.8.1YELLOW · PLAN IT INat.yawk.lz4:lz4-javayawkat LZ4 Java provides LZ4compression for Java. From1.7.0 until 1.11.4,net.jpountz.util.Native.load()uses File.createTempFile tocreate an exclusive temporary.lck file but derives the…Where it standsNo known exploitationCONNECTS TOSame weaknessCWE-789 (CWE-789)44 other warnings in 30 days →
Story map: the flaws, the fix, how it unfolded and what it connects to. Boxes link to the record or article.

At a glance

at.yawk.lz4:lz4-java: Yellow, plan it in. yawkat LZ4 Java provides LZ4 compression for Java. From 1.7.0 until 1.11.4, net.jpountz.util.Native.load() uses File.createTempFile to create an exclusive temporary .lck file but derives the native-library path by removing the suffix, then FileOutputStream opens that predictable path without exclusive creation, allowi…

The flaws

  • CVE-2026-106453: Yawkat LZ4 Java: LZ4DecompressorWithLength allocates the unvalidated size from the 4-byte length header, so a 5-byte input triggers a 1 GiB allocation and OutOfMemoryError (CVSS 5.3 · EPSS 0%)
  • CVE-2026-106451: Yawkat LZ4 Java: Native library extraction to a shared temporary directory is vulnerable to file replacement by another local user (CVSS 7.3 · EPSS 0%)
  • CVE-2026-106450: Yawkat LZ4 Java: LZ4FrameInputStream reallocates block buffers for every frame, allowing CPU and GC amplification from small inputs (CVSS 5.3 · EPSS 0%)
  • CVE-2026-106452: Yawkat LZ4 Java: LZ4BlockInputStream allocates an unvalidated compressed length from the stream header (CVSS 5.3 · EPSS 0%)

The fix

Upgrade at.yawk.lz4:lz4-java: 1.11.2 · 1.11.4 or later on your release line

Who is exposed: at.yawk.lz4:lz4-java (maven) <= 1.11.3; org.lz4:lz4-java (maven) >= 1.7.0, <= 1.8.1

Where it stands

  • No known exploitation

Connects to

Why it is Yellow

  • CVSS 5.3 medium
  • On your watchlist: Maven

Affected packages

PackageEcosystemVulnerableFixed in
at.yawk.lz4:lz4-javamaven<= 1.11.11.11.2
org.lz4:lz4-javamaven<= 1.8.1No fix yet

References

Original description

yawkat LZ4 Java provides LZ4 compression for Java. Prior to 1.11.2, LZ4DecompressorWithLength uses getDecompressedLength to trust the four-byte decompressed-length header before validating the compressed input, allowing a five-byte attacker-supplied input whose header declares a large output size to request up to approximately 2 GiB and exhaust the JVM heap. Convenience overloads backed by LZ4FastDecompressor or LZ4SafeDecompressor allocate the untrusted size, while overloads that write to a caller-provided destination buffer are not affected because the caller controls the destination size. This issue is fixed in version 1.11.2.

Last activity 6 Oct 2026. Patch Forecast updates every hour.