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. 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 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.
Products Associated with CVE-2026-45232
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Affected Versions
RsyncProject rsync:- Before 3.4.3 is affected.
Exploit Probability
EPSS (Exploit Prediction Scoring System) scores estimate the probability that a vulnerability will be exploited in the wild within the next 30 days. The percentile shows you how this score compares to all other vulnerabilities.