==========================================================================
Ubuntu Security Notice USN-8349-2
June 08, 2026

rsync regression
==========================================================================

A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 26.04 LTS
- Ubuntu 25.10
- Ubuntu 24.04 LTS
- Ubuntu 22.04 LTS

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 extended attributes. An attacker could possibly use this
 issue to cause a denial of service. (CVE-2026-41035)

 It was discovered that rsync performed reverse-DNS lookups after
 chrooting in some daemon configurations. A remote attacker could
 possibly use this issue to bypass hostname-based access controls and
 access network services. (CVE-2026-43617)

 Omar Elsayed discovered that rsync did not properly check for integer
 overflows while decoding compressed tokens. A remote attacker could
 possibly use this issue to obtain sensitive information.
 (CVE-2026-43618)

 Andrew Tridgell discovered that rsync did not fully fix a symlink race
 condition in path-based system calls for daemons configured without
 chroot protection. A local attacker could possibly use this issue to
 overwrite files, obtain sensitive information, or escalate privileges.
 (CVE-2026-43619)

 Pratham Gupta discovered that rsync did not properly validate an index
 while processing file lists. A remote attacker could possibly use this
 issue to cause rsync to crash, resulting in a denial of service.
 (CVE-2026-43620)

 Michal Ruprich discovered that rsync contained an off-by-one error
 while handling HTTP proxy responses. An attacker able to intercept network
 communications or a malicious proxy server could possibly use this issue to
 cause a denial of service. (CVE-2026-45232)

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.

References:
  https://ubuntu.com/security/notices/USN-8349-2
  https://ubuntu.com/security/notices/USN-8349-1
  https://launchpad.net/bugs/2155874

Package Information:
  https://launchpad.net/ubuntu/+source/rsync/3.4.1+ds1-7ubuntu0.3
  https://launchpad.net/ubuntu/+source/rsync/3.4.1+ds1-5ubuntu1.3
  https://launchpad.net/ubuntu/+source/rsync/3.2.7-1ubuntu1.5
  https://launchpad.net/ubuntu/+source/rsync/3.2.7-0ubuntu0.22.04.7