Rsync <3.5.0 Symlink Race Condition Enables Local Privilege Escalation
CVE-2026-53799 Published on August 13, 2026
rsync < 3.5.0 Symlink Race Condition via ACL/xattr Application
rsync before 3.5.0 contains a symlink race condition vulnerability that allows local attackers to cause rsync to apply arbitrary ACLs or extended attributes to unintended files by substituting a symlink at a predictable destination path between the file write and the subsequent acl_set_file() or lsetxattr() call. Attackers can exploit this timing window to redirect ACL and xattr application through a crafted symlink to files outside the intended destination tree, potentially granting elevated permissions and enabling local privilege escalation.
Vulnerability Analysis
CVE-2026-53799 can be exploited with local system access, and requires small amount of user privileges. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity and availability.
Weakness Types
What is an insecure temporary file Vulnerability?
The software attempts to access a file based on the filename, but it does not properly prevent that filename from identifying a link or shortcut that resolves to an unintended resource.
CVE-2026-53799 has been classified to as an insecure temporary file vulnerability or weakness.
What is a TOCTTOU Vulnerability?
The software checks the state of a resource before using that resource, but the resource's state can change between the check and the use in a way that invalidates the results of the check. This can cause the software to perform invalid actions when the resource is in an unexpected state. This weakness can be security-relevant when an attacker can influence the state of the resource between check and use. This can happen with shared resources such as files, memory, or even variables in multithreaded programs.
CVE-2026-53799 has been classified to as a TOCTTOU vulnerability or weakness.
Products Associated with CVE-2026-53799
Want to know whenever a new CVE is published for Samba Rsync? stack.watch will email you.
Affected Versions
RsyncProject rsync:- Before and including 3.4.4 is affected.
- Version 3.5.0 is unaffected.