Bug 2547137 (CVE-2026-106451)

Summary:	CVE-2026-106451 org.lz4/lz4-java: lz4-java: Arbitrary code execution via insecure temporary file handling
Product:	[Other] Security Response	Reporter:	OSIDB Bzimport <bzimport>
Component:	vulnerability	Assignee:	Product Security DevOps Team <prodsec-dev>
Status:	NEW ---	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	ant, anujha, asoldano, asyoung, bbaranow, bmaxwell, bstansbe, ccranfor, cescoffi, cmah, dlofthou, ewittman, fmariani, fmongiar, gmalinko, gsmet, gtanzill, istudens, ivassile, iweiss, janstey, jbuscemi, jhollowa, jmartisk, jnethert, jpechane, jwon, kaycoth, manderse, mcarlett, mosmerov, msvehla, nipatil, nwallace, olubyans, ozzy, pantinor, pberan, pdelbell, pesilva, pjindal, pmackay, prichard, rguimara, rhel-process-autobot, rkubis, rstancel, rstepani, sbiarozk, sthirugn, tcunning, thjenkin, varjain, vdosoudi, watson-tool-maintainers, yfang
Target Milestone:	---	Keywords:	Security
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Hardware:	All
OS:	Linux
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Doc Text:	A flaw was found in lz4-java. When extracting native libraries, the application writes temporary files to a shared directory using predictable file paths without exclusive file creation controls. A local attacker with access to the shared directory could exploit this race condition to replace the native library before it is loaded, potentially leading to arbitrary code execution with the privileges of the running application.	Story Points:	---
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	2550353
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Description OSIDB Bzimport 2026-10-06 20:02:40 UTC

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, allowing another local user with access to the same shared temporary directory to create or replace the library file before System.load() uses it. Successful exploitation depends on shared-directory permissions, host protections, and winning the race, and can execute native code as the victim; hardened systems may instead cause library loading to fail and fall back to Java implementations. Configurations using a system library, a private java.io.tmpdir, or Java-only implementations are not affected. This issue is fixed in version 1.11.4.