Rsync version 3.4.2 and prior contain a receiver-side out-of-bounds array read vulnerability in recv_files() in receiver.c that allows a malicious rsync server to crash the rsync client process. Attackers can exploit the vulnerability by setting CF_INC_RECURSE in compatibility flags and sending a specially crafted file list where the first sorted entry is not the leading dot directory, followed by a transfer record with ndx=0 and an iflag word without ITEM_TRANSFER, causing the receiver to read 8 bytes before the allocated pointer array and dereference an invalid pointer at an unmapped address, resulting in a deterministic SIGSEGV crash of the rsync client.
CVSS Score
6.9
EPSS Score
0.004
Published
2026-05-20
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.
CVSS Score
2.1
EPSS Score
0.003
Published
2026-05-20
In rsync 3.0.1 through 3.4.1, receive_xattr relies on an untrusted length value during a qsort call, leading to a receiver use-after-free. The victim must run rsync with -X (aka --xattrs). On Linux, many (but not all) common configurations are vulnerable. Non-Linux platforms are more widely vulnerable.
CVSS Score
7.4
EPSS Score
0.004
Published
2026-04-16
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