Medium severity · published Oct 6, 2026
CVE-2026-106452
yawkat LZ4 Java: LZ4BlockInputStream allocates an unvalidated compressed length from the stream header
5.3
CVSS
0.5%
EPSS
No
On KEV
Description
yawkat LZ4 Java provides LZ4 compression for Java. Prior to 1.11.2, net.jpountz.lz4.LZ4BlockInputStream refill() validates that the compressedLen field in a legacy LZ4Block header is nonnegative but allocates a compressed-input buffer of that attacker-controlled size before reading payload data, allowing a header-only stream to request a near-2 GiB allocation and exhaust the JVM heap. Canonical writers emit raw blocks when compression is not smaller than the original block, but vulnerable readers accept non-canonical oversized compressed blocks. This issue is fixed in version 1.11.2.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
None
Integrity
None
Availability
Low
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.5% · higher than 39% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
LZ
lz4-java · yawkat
< 1.11.2 · source: vendor
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-106452
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-106452
x_refsource_CONFIRM
https://github.com/yawkat/lz4-java/security/advisories/GHSA-4v53-57pg-c464
x_refsource_MISC
https://github.com/yawkat/lz4-java/commit/bb83dd16163cdb71231af06b0a5651881148a634
x_refsource_MISC
https://github.com/yawkat/lz4-java/releases/tag/v1.11.2
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