CVE-2026-45232: Rsync < 3.4.3 Off-by-One Stack Write via HTTP Proxy
Last updated 22 May 2026
Other sources
Rsync < 3.4.3 Off-by-One Stack Write via HTTP Proxy
— Microsoft
Rsync versions before 3.4.3 contain an off-by-one out-of-bounds stack write vulnerability in the establishproxyconnection() 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 RSYNCPROXY environment variable is set.
— Launchpad
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/rsyncto a version that resolves this vulnerability.Fixed in 3.4.3+ds1-2 - Upgrade
Upgrade
rsyncto a version that resolves this vulnerability.Fixed in 3.4.3 - Upgrade
Upgrade
rsyncto a version that resolves this vulnerability.Patch CVE-2026-29518 - Upgrade
Upgrade
rsyncto a version that resolves this vulnerability.Patch CVE-2026-43617 - Upgrade
Upgrade
rsyncto a version that resolves this vulnerability.Patch CVE-2026-43618 - Upgrade
Upgrade
rsyncto a version that resolves this vulnerability.Patch CVE-2026-43619 - Upgrade
Upgrade
rsyncto a version that resolves this vulnerability.Patch CVE-2026-43620 - Upgrade
Upgrade
rsyncto a version that resolves this vulnerability.Patch CVE-2026-45232
Event History
Frequently Asked Questions
What is the severity of CVE-2026-45232?
CVE-2026-45232 is classified as a medium severity vulnerability due to its potential to allow stack memory corruption.
How do I fix CVE-2026-45232?
To fix CVE-2026-45232, upgrade to rsync version 3.4.3 or later.
Who is affected by CVE-2026-45232?
Rsync versions prior to 3.4.3 are affected by CVE-2026-45232.
What type of vulnerability is CVE-2026-45232?
CVE-2026-45232 is an off-by-one stack write vulnerability that occurs in the establish_proxy_connection() function of rsync.
What can attackers do with CVE-2026-45232?
Attackers can exploit CVE-2026-45232 to send malformed HTTP proxy responses, which could corrupt stack memory and potentially lead to remote code execution.