Ubuntu Rsync Critical Denial of Service Vulnerabilities 2025-10158

ubuntu

June 8, 2026

USN-8349-1 introduced regressions in rsync.

Summary

USN-8349-1 introduced regressions in rsync.

Software Description:

- rsync: fast, versatile, remote (and local) file-copying tool

Details:

USN-8349-1 fixed vulnerabilities in rsync. The update introduced multiple

regressions in rsync functionality. This update fixes the problem.

Original advisory details:

Calum Hutton discovered that rsync contained a heap-based out-of-bounds

read when handling file transfers. A remote attacker with read access

to an rsync server could possibly use this issue to cause a denial of

service. (CVE-2025-10158)

Batuhan Sancak, Damien Neil, and Michael Stapelberg discovered that

rsync daemons configured without chroot protection were exposed to a

race condition on parent path components. A local attacker with write

access to a module could possibly use this issue to overwrite files,

obtain sensitive information, or escalate privileges.

(CVE-2026-29518)

It was discovered that rsync did not properly validate a length value

while sorting ex...

Read the Full Advisory

Topics Covered

security advisory denial of service information leak Ubuntu rsync local attack

Update Instructions

The problem can be corrected by updating your system to the following
package versions:

Ubuntu 26.04 LTS
  rsync                           3.4.1+ds1-7ubuntu0.3

Ubuntu 25.10
  rsync                           3.4.1+ds1-5ubuntu1.3

Ubuntu 24.04 LTS
  rsync                           3.2.7-1ubuntu1.5

Ubuntu 22.04 LTS
  rsync                           3.2.7-0ubuntu0.22.04.7

After a standard system update you need to restart rsync daemons if
configured to make all the necessary changes.