Vulnerability · Published Oct 6, 2026 · Assigned by GitHub_M

CVE-2026-106450yawkat LZ4 Java: LZ4FrameInputStream reallocates block buffers for every frame, allowing CPU and GC amplification from small inputs

Medium 5.3

In plain English

A medium-severity resource allocation without limits 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 40% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)5.3Medium

Exploit odds (30 days)0.5%top 60.4% 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 1.11.4, net.jpountz.lz4.LZ4FrameInputStream readHeader() allocates two new 4 MiB block buffers whenever a maximum-block-size frame header is read, and the default concatenated-frame mode allows attacker-controlled streams containing many minimal empty frames to trigger roughly 8 MiB of allocation for every 11 input bytes. The stream produces no decompressed output while consuming CPU and garbage-collection time, so decompressed-size limits do not mitigate the issue; readSingleFrame mode is not affected. This issue is fixed in version 1.11.4.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Debian:12	lz4-java	no fix listed	DEBIAN-CVE-2026-106450
Debian:13	lz4-java	no fix listed	DEBIAN-CVE-2026-106450
Debian:14	lz4-java	no fix listed	DEBIAN-CVE-2026-106450
Maven	at.yawk.lz4:lz4-java	1.11.4	GHSA-gm45-99xc-r7wv
Maven	org.lz4:lz4-java	no fix listed	GHSA-gm45-99xc-r7wv
Ubuntu:22.04:LTS	lz4-java	no fix listed	UBUNTU-CVE-2026-106450
Ubuntu:24.04:LTS	lz4-java	no fix listed	UBUNTU-CVE-2026-106450
Ubuntu:26.04:LTS	lz4-java	no fix listed	UBUNTU-CVE-2026-106450
Ubuntu:26.10	lz4-java	no fix listed	UBUNTU-CVE-2026-106450

Affected products (as reported)

Vendor	Product	Versions
yawkat	lz4-java	< 1.11.4

Weakness: CWE-770 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L

References

https://github.com/yawkat/lz4-java/security/advisories/GHSA-gm45-99xc-r7wv x_refsource_CONFIRM
https://github.com/yawkat/lz4-java/commit/2acc0ec1ead226145c62a817c18c8ed49233a283 x_refsource_MISC
https://github.com/yawkat/lz4-java/releases/tag/v1.11.4 x_refsource_MISC