Bug 2546590 (CVE-2026-105840)

Summary: CVE-2026-105840 lrzsz: lrzsz: Arbitrary file overwrite via absolute path traversal in restricted mode
Product: [Other] Security Response Reporter: OSIDB Bzimport <bzimport>
Component: vulnerabilityAssignee: Product Security DevOps Team <prodsec-dev>
Status: NEW --- QA Contact:
Severity: high Docs Contact:
Priority: high    
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 lrzsz. The lrz receive utility fails to properly sanitize absolute file paths in restricted mode, only checking for relative path traversal sequences. A remote attacker transmitting files can exploit this vulnerability to write or overwrite arbitrary files outside the intended directory with the permissions of the receiving user.
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
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Bug Depends On: 2547294    
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Description OSIDB Bzimport 2026-10-06 13:42:44 UTC
lrzsz before 0.13.0 contains a path traversal vulnerability in the lrz receive utility's restricted mode that allows malicious ZMODEM senders to write files outside the current directory using absolute pathnames. Because checkpath() in src/lrz.c only rejects '../' sequences unless built with --enable-pubdir, attackers can send files named with absolute paths to overwrite any file writable by the receiving user.