SB2026060475 - Use-after-free in Rsync

Description

This security bulletin contains information about 1 vulnerability.

1) Use-after-free (CVE-ID: CVE-2026-41035)

CWE-ID: CWE-416 - Use After Free

CVSSv4: CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green

The vulnerability allows a remote attacker to cause a denial of service and disclose sensitive information.

The vulnerability exists due to use-after-free in receive_xattr() in xattrs.c when processing xattr data from a malicious rsync sender. A remote attacker can send specially crafted xattr metadata to cause a denial of service and disclose sensitive information.

Exploitation requires xattr transfer to be enabled. On Linux, additional conditions apply: the receiver must use --fake-super or an xattr filter that passes non-user namespace xattrs; on FreeBSD and macOS, configurations using xattrs are affected when more than one xattr is processed.

Remediation

Install update from vendor's website.

References

• https://github.com/RsyncProject/rsync/issues/871
• https://github.com/RsyncProject/rsync/releases
• https://www.openwall.com/lists/oss-security/2026/04/16/2
• http://www.openwall.com/lists/oss-security/2026/04/16/9
• http://www.openwall.com/lists/oss-security/2026/04/22/3