Rsync <3.4.3: OOB stack write in establish_proxy_connection()
CVE-2026-45232 Published on May 20, 2026
Rsync < 3.4.3 Off-by-One Stack Write via HTTP Proxy
Rsync versions before 3.4.3 contain an off-by-one out-of-bounds stack write vulnerability in the establish_proxy_connection() function in socket.c that allows network attackers to corrupt stack memory by sending a malformed HTTP proxy response. Attackers can exploit this by positioning themselves between the client and proxy or controlling the proxy server to send a response line of 1023 or more bytes without a newline terminator, causing a null byte to be written to an out-of-bounds stack address when the RSYNC_PROXY environment variable is set.
Vulnerability Analysis
CVE-2026-45232 is exploitable with network access, requires user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to have no impact on confidentiality and integrity, and a small impact on availability.
Weakness Type
What is an off-by-five Vulnerability?
A product calculates or uses an incorrect maximum or minimum value that is 1 more, or 1 less, than the correct value.
CVE-2026-45232 has been classified to as an off-by-five vulnerability or weakness.
Affected Versions
RsyncProject rsync:- Before 3.4.3 is affected.