Rsyncproject Rsync vulnerabilities

39 vulnerabilities

Known vulnerabilities in Rsyncproject Rsync, newest first, with CVSS severity, EPSS, KEV listings, ransomware use and the affected versions.

6.3CVE-2026-43617alpinersync+4
EPSS score
0.32%
Rsync version 3.4.2 and prior contain an authorization bypass vulnerability in the rsync daemon's hostname-based access control list enforcement when configured with chroot. Attackers can bypass hostname-based deny rules by controlling the PTR record for their source IP address, allowing connections from hostnames that administrators intended to deny when reverse DNS resolution fails and defaults to UNKNOWN.
8.1CVE-2026-43618alpinersync+4
EPSS score
0.80%
Rsync version 3.4.2 and prior contain an integer overflow vulnerability in the compressed-token decoder where a 32-bit signed counter is not checked for overflow, allowing a malicious sender to trigger an overflow that causes the receiver process to read and return data from outside the intended buffer bounds. Attackers can exploit this vulnerability to disclose process memory contents including environment variables, passwords, heap and stack data, and library memory pointers, significantly reducing ASLR effectiveness and facilitating further exploitation.
6.9CVE-2026-43620alpinersync+4
EPSS score
0.46%
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.
7.2CVE-2026-43619alpinersync+4
EPSS score
0.13%
Rsync version 3.4.2 and prior contain symlink race condition vulnerabilities in path-based system calls including chmod, lchown, utimes, rename, unlink, mkdir, symlink, mknod, link, rmdir, and lstat that allow local attackers to redirect operations to files outside the exported rsync module. Attackers with local filesystem access can exploit the timing window between path resolution and syscall execution by swapping symlinks to apply sender-supplied permissions, ownership, timestamps, or filenames to arbitrary files outside the intended module boundary on rsync daemons configured with 'use chroot = no'.
7.2CVE-2026-53799alpinersync+4
EPSS score
0.12%
rsync before 3.5.0 contains a symlink race condition vulnerability that allows local attackers to cause rsync to apply arbitrary ACLs or extended attributes to unintended files by substituting a symlink at a predictable destination path between the file write and the subsequent acl_set_file() or lsetxattr() call. Attackers can exploit this timing window to redirect ACL and xattr application through a crafted symlink to files outside the intended destination tree, potentially granting elevated permissions and enabling local privilege escalation.
8.2CVE-2026-53801alpinersync+4
EPSS score
0.29%
rsync before 3.5.0 contains a symlink race condition vulnerability in the sender's directory scanning logic that allows attackers to cause the sender to enumerate and transfer files outside the module root's intended subtree. Attackers who can create or manipulate symlinks in a path component of the scanned tree can replace a symlink with a directory entry pointing outside the module root between the lstat() call and the subsequent opendir() call, exposing files beyond the intended root in both daemon-mode and non-daemon sender-side scanning.
6.9CVE-2026-53788alpinersync+3
EPSS score
0.27%
rsync before 3.5.0 contains a newline injection vulnerability in the name-converter uid/gid mapping interface that allows local attackers to forge protocol messages by creating user or group names containing newline characters. Attackers can inject malicious newline characters into names communicated over the pipe-based line-oriented protocol to cause the rsync daemon to process attacker-influenced data as legitimate protocol input, corrupting uid/gid mapping logic.
8.5CVE-2026-53803alpinersync+4
EPSS score
0.23%
rsync before 3.5.0 contains a symlink following vulnerability that allows local attackers to overwrite arbitrary files by placing a symlink at a predictable output path such as --log-file, --write-batch, or daemon-mode log and statistics paths. Attackers can exploit rsync's failure to reject symlinks during ancillary file writes to redirect output to arbitrary filesystem locations, achieving local privilege escalation on installations where rsync runs with elevated privileges such as setuid or privileged daemon configurations.
8.1CVE-2026-53795alpinersync+4
EPSS score
0.40%
rsync before 3.5.0 contains an arbitrary file write vulnerability that allows attackers to write files outside the intended destination tree by specifying an absolute path via --temp-dir or --link-dest options. The rename-confinement logic is bypassed when these options resolve to paths outside the destination tree, enabling attacker-controlled values to write files to arbitrary locations accessible to the rsync process.
6.9CVE-2026-53798alpinersync+4
EPSS score
0.43%
rsync before 3.5.0 contains a privilege confusion vulnerability in the name-converter subprocess uid/gid mapping that allows local attackers to cause transferred files to be owned by root by influencing name-converter responses to return empty values. When the name-converter subprocess returns an empty response for a uid or gid lookup, rsync incorrectly interprets it as a successful resolution to uid/gid 0 (root) rather than a lookup failure, and if the name-converter also signals fake super-user status, rsync proceeds with root ownership assignments for transferred files.
9.1CVE-2026-53793alpinersync+3
EPSS score
0.39%
rsync before 3.5.0 contains a path confinement bypass vulnerability that allows remote clients to escape the intended inner-module root confinement by constructing paths that resolve outside the chroot boundary when the module root contains a /./ boundary marker. Attackers can exploit improper handling of the /./ notation or forge delta-basis transfers referencing xname paths that cross the /./ boundary to gain unauthorized read or write access to files outside the module's subtree.
6.3CVE-2026-53796alpinersync+3
EPSS score
0.13%
rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the non-daemon receiver's destination directory handling that allows an attacker who can manipulate destination path parent components to redirect file writes to unintended locations. Attackers can substitute a symlink for a component of the destination path between the path resolution and chdir() call, causing the receiver's working directory to be established outside the intended destination tree so that subsequent relative-path file writes land in unintended filesystem locations.
5.7CVE-2026-53800alpinersync+4
EPSS score
0.14%
rsync before 3.5.0 contains a symlink race condition vulnerability in the --remove-source-files feature that allows attackers with symlink creation access to cause arbitrary file deletion. Attackers can atomically substitute a symlink for a source file between transfer completion and the unlink() call, causing rsync to delete the symlink target rather than the intended source file.
6.9CVE-2026-53786alpinersync+4
EPSS score
0.40%
rsync before 3.5.0 contains a filter rule bypass vulnerability that allows authenticated clients to override module-level filter restrictions by supplying malicious --filter merge file directives. Attackers can inject client-side merge file directives during filter evaluation to introduce rules that supersede daemon module-level restrictions, gaining access to files the module filter was intended to exclude.
8.1CVE-2026-53789alpinersync+4
EPSS score
0.36%
rsync before 3.5.0 contains an improper path handling vulnerability that allows a malicious sender to expand the scope of --delete operations beyond the intended destination subtree by sending a crafted file list that causes rsync to reclassify implied parent directory entries or treat synthetic paths as the transfer root. Attackers can exploit multiple variants including implied parent reclassification, synthetic root path construction, legacy protocol behavior below version 30, and non-directory root handling to cause the receiver to delete files outside the authorized destination directory.
5.7CVE-2026-53797alpinersync+4
EPSS score
0.14%
rsync before 3.5.0 contains a symlink race condition vulnerability in the sender's source tree traversal that allows an attacker who can manipulate a parent directory of the source tree to redirect file reads to unintended paths. Attackers can atomically replace a parent directory component with a symlink pointing outside the source root between path resolution and file open operations to disclose file contents outside the intended transfer root.
9.1CVE-2026-53791alpinersync+4
EPSS score
0.50%
rsync daemon before 3.5.0 contains an IP address spoofing vulnerability that allows unauthenticated remote attackers to bypass IP-based access controls by sending a crafted PROXY protocol header with a forged source address. Attackers who can connect directly to the rsync daemon can inject a spoofed source IP in the PROXY protocol header to circumvent hosts allow/deny rules, gaining unauthorized access that would otherwise be blocked based on their real source address.
7.1CVE-2026-53785alpinersync+3
EPSS score
0.19%
rsync before 3.5.0 contains a path traversal vulnerability that allows a malicious sender to write files outside the intended destination directory tree by crafting relative paths with symlink components in --relative mode. The make_path() function follows symlinks pointing outside the destination tree while creating intermediate directories without verifying that created paths remain within the destination boundary, enabling arbitrary file writes on the receiver's filesystem.
7.1CVE-2026-53792alpinersync+3
EPSS score
0.31%
rsync before 3.5.0 contains an out-of-bounds read vulnerability in the sender-side block matching logic that allows a malicious receiver to trigger memory access before the start of an allocated buffer by sending a crafted checksum block with a length of zero. Attackers can send a specially crafted checksum set containing a zero-length block to cause a negative offset calculation during delta computation, resulting in an out-of-bounds read of file data buffer memory on the sender side.
8.4CVE-2026-53784alpinersync+4
EPSS score
0.24%
rsync before 3.5.0 contains a path traversal vulnerability that allows remote clients to access files outside the intended module root when use chroot is disabled and the module root path or a component of it is a symlink. The daemon calls chdir() to the module root at session initialization without resolving symlinks via realpath() or equivalent, causing subsequent relative-path operations to reference files relative to the symlink target rather than the intended module root, enabling unauthorized file access.