High severity · published Dec 5, 2025
CVE-2025-66566
yawkat LZ4 Java has a possible information leak in Java safe decompressor
8.2
CVSS
0.6%
EPSS
No
On KEV
Description
yawkat LZ4 Java provides LZ4 compression for Java. Insufficient clearing of the output buffer in Java-based decompressor implementations in lz4-java 1.10.0 and earlier allows remote attackers to read previous buffer contents via crafted compressed input. In applications where the output buffer is reused without being cleared, this may lead to disclosure of sensitive data. JNI-based implementations are not affected. This vulnerability is fixed in 1.10.1.
Exploitation
Is it being used?
Exploit prediction (EPSS)0.6% · higher than 49% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LZ
lz4-java · yawkat
< 1.10.1 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2025-66566
CVE.org
https://www.cve.org/CVERecord?id=CVE-2025-66566
github.com
https://github.com/yawkat/lz4-java/commit/33d180cb70c4d93c80fb0dc3ab3002f457e93840
github.com
https://github.com/yawkat/lz4-java/security/advisories/GHSA-cmp6-m4wj-q63q
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