Off-by-one in Rsync - CVE-2026-45232
Published: June 1, 2026
Vulnerability identifier: #VU133149
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N/E:U/U:Green
CVE-ID: CVE-2026-45232
CWE-ID: CWE-193
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Samba
Affected software:
Rsync
Rsync
Detailed vulnerability description
The vulnerability allows a remote attacker to cause a denial of service.
The vulnerability exists due to an off-by-one out-of-bounds stack write in establish_proxy_connection() in socket.c when processing the first response line from an HTTP CONNECT proxy. A remote attacker can return a pathological proxy response line without a newline terminator to cause a denial of service.
The issue is reachable only on the client side when RSYNC_PROXY is set, and the written byte is a fixed \0.
How to mitigate CVE-2026-45232
Install security update from vendor's website.