Bug 2531026

Summary: CVE-2026-29518 rsync-bpc: TOCTOU symlink race condition allowing local privilege escalation in daemon mode without chroot. [epel-all]
Product: [Fedora] Fedora EPEL Reporter: Patrick Del Bello <pdelbell>
Component: rsync-bpcAssignee: Richard Shaw <hobbes1069>
Status: NEW --- QA Contact: Fedora Extras Quality Assurance <extras-qa>
Severity: high Docs Contact:
Priority: high    
Version: epel10CC: hobbes1069
Target Milestone: ---Keywords: Security, SecurityTracking
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard: {"flaws": ["18aada90-6d23-4616-ac21-5e3f4aa6a555"]}
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oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
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Bug Depends On:    
Bug Blocks: 2469055    

Description Patrick Del Bello 2026-09-09 15:29:17 UTC 
Disclaimer: Community trackers are created by Red Hat Product Security team on a best effort basis. Package maintainers are required to ascertain if the flaw indeed affects their package, before starting the update process.

A flaw was found in rsync. An rsync daemon configured with "use chroot = no" is exposed
to a time-of-check / time-of-use race on parent path components. A local
attacker with write access to a module can replace a parent directory
component with a symlink between the receiver's check and its open(),
redirecting reads (basis-file disclosure) and writes (file overwrite)
outside the module. Under elevated daemon privilege this allows privilege
escalation. Default "use chroot = yes" is not exposed.