Bug 2571637 (CVE-2026-124745)

Summary: CVE-2026-124745 busybox: tar deferred hardlink target resolved through a deferred symlink escapes the extraction directory
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: medium Docs Contact:
Priority: medium    
Version: unspecifiedCC: rhel-process-autobot, watson-tool-maintainers
Target Milestone: ---Keywords: Security
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Hardware: All   
OS: Linux   
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A flaw was found in BusyBox. When extracting an archive, the tar utility improperly resolves deferred hardlink targets across symbolic links pointing outside the intended extraction directory. An attacker could provide a specially crafted archive that links to sensitive files outside the extraction tree, allowing subsequent extraction operations to overwrite arbitrary files on the system.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2571670, 2571671    
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Description OSIDB Bzimport 2026-11-11 11:19:08 UTC 
A flaw was found in BusyBox's tar. The target of a deferred hardlink is resolved through deferred symlinks in its directory components: a symlink entry pointing outside the extraction directory, followed by a hardlink entry whose target passes through that symlink, makes the created hardlink refer to a file outside the extraction directory. A crafted archive can exploit this to pull an arbitrary outside file into the extraction tree as a hardlink; a second archive extracted into the same directory with an overwriting extractor could then replace the outside file's content.