Insertion of Sensitive Information Into Sent Data Affecting net.jpountz.lz4:lz4 package, versions [0,]
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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Test your applications- Snyk IDSNYK-JAVA-NETJPOUNTZLZ4-14219377
- published7 Dec 2025
- disclosed5 Dec 2025
- creditsimonresch
Introduced: 5 Dec 2025
CVE-2025-66566 (opens in a new tab)How to fix?
There is no fixed version for net.jpountz.lz4:lz4.
Overview
net.jpountz.lz4:lz4 is a package for LZ4 compression for Java
Affected versions of this package are vulnerable to Insertion of Sensitive Information Into Sent Data in the decompression process when the output buffer is reused without being cleared. An attacker can access sensitive information from previous buffer contents by providing crafted compressed input.
Note:
- JNI implementations are not vulnerable.
LZ4Factory.safeInstance(),LZ4Factory.unsafeInstance(), andLZ4Factory.fastestJavaInstance()are all vulnerable.nativeInstance().fastDecompressor()is vulnerable butnativeInstance().safeDecompressor()is not.- This vulnerability is distinct from the one described in CVE-2025-12183, and was discovered during follow-up research.
Workaround
This vulnerability can be mitigated by zeroing the output buffer before passing it to the decompression function.