CVE-2026-45232

A flaw was found in rsync. A network attacker can exploit an off-by-one out-of-bounds stack write vulnerability in the establish_proxy_connection() function by sending a malformed HTTP proxy response. This occurs when the RSYNC_PROXY environment variable is set and the attacker sends a response line of 1023 or more bytes without a newline terminator. This can corrupt stack memory, potentially leading to a Denial of Service (DoS).

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

To mitigate this issue, ensure that the RSYNC_PROXY environment variable is not set. If rsync is configured to use an HTTP proxy via this variable, unsetting it will prevent exploitation. To unset the RSYNC_PROXY environment variable for the current session, use: unset RSYNC_PROXY. For a more permanent solution, ensure that RSYNC_PROXY is not defined in system-wide or user-specific environment configuration files. Note that this mitigation will disable rsync's ability to use an HTTP proxy, which may impact functionality if proxy usage is required.