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.
rsync before 3.5.0 contains a time-of-check to time-of-use (TOCTOU) race condition vulnerability in the rrsync restricted shell wrapper that allows authenticated clients to escape enforced directory restrictions by substituting a symlink for a path component after validation but before transfer processing. Attackers can additionally leverage unrestricted flags such as --copy-unsafe-links, -D, and --log-file through rrsync to read or write files outside the permitted directory subtree.
rsync before 3.5.0 contains multiple command and argument injection vulnerabilities that allow attackers to execute arbitrary commands by supplying malicious input through several code paths, including the RSYNCCONNECTPROG environment variable, daemon hooks, the rsync-ssl wrapper, and remote-shell command newline injection. Attackers can inject shell metacharacters or newline characters into unsanitized user-supplied values such as hostnames and hostspecs to execute arbitrary commands under the privileges of the rsync process or the invoking user.
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 makepath() 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.
rsync 3.1.0 < 3.5.0 Access Control Bypass via DNS Resolution Failure
rsync 3.2.0 through 3.2.3 (openssl mode) and rsync-ssl through 3.4.4 (stunnel mode) contain a TLS certificate validation vulnerability that allows on-path attackers to intercept encrypted sessions by presenting self-signed or otherwise invalid certificates. Attackers can exploit the failure to validate server TLS certificates against a trusted CA or verify certificate hostname matching to decrypt or tamper with rsync session content without detection by the client.
rsync 2.3.3 < 3.5.0 Path Traversal via --partial-dir/--backup-dir Symlink
rsync 3.0.1 < 3.5.0 Heap Out-of-Bounds Write via readargs()
In rsync 3.0.1 through 3.4.1, receivexattr 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.
In rsync 3.0.1 through 3.4.1, receivexattr 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.
A flaw was found in rsync. An authenticated daemon peer can exploit an integer overflow vulnerability in the compressed-token decoder. By carefully manipulating the compressed-token, a malicious sender can trigger an overflow, leading to remote memory disclosure. This allows an attacker to leak sensitive process memory contents, including environment variables, passwords, and memory pointers, which significantly weakens Address Space Layout Randomization (ASLR) and can facilitate further exploitation.
A flaw was found in rsync. An rsync daemon configured with "use chroot = no" is exposed to a time-of-check / time-of-use race on parent path components. A local attacker with write access to a module can replace a parent directory component with a symlink between the receiver's check and its open(), redirecting reads (basis-file disclosure) and writes (file overwrite) outside the module. Under elevated daemon privilege this allows privilege escalation. Default "use chroot = yes" is not exposed.
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.
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.
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.
rsync before 3.5.0 contains an arbitrary file read vulnerability that allows attackers to read files accessible to the rsync daemon process by exploiting symlink following in input configuration file handling including --files-from, --password-file, and filter merge files. Attackers can place a symlink at a predictable --files-from or --password-file path, or supply a --files-from path that escapes the daemon module root, to read arbitrary files accessible to the rsync process.
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.
rsync 3.4.2 < 3.5.0 DoS via --zt Zstandard Compression Thread Exhaustion
rsync 3.0.0 < 3.5.0 Daemon Crash via Malformed File List Entry
rsync 3.1.0 before 3.5.0 contains an authorization bypass in auth users directive parsing. The auth users parser uses comma-only tokenization when splitting the user list, which fails to correctly handle entries of the form @Group Name where the group name contains a space. The space within the group name causes the parser to split the entry at the space boundary, discarding the deny rule associated with the group. An authenticated user whose username or group membership would be denied by an @Group Name auth users entry can connect to a restricted module because the deny rule is silently discarded during parsing.
A flaw was found in rsync. An rsync daemon configured with "use chroot = no" is exposed to a time-of-check / time-of-use race on parent path components. A local attacker with write access to a module can replace a parent directory component with a symlink between the receiver's check and its open(), redirecting reads (basis-file disclosure) and writes (file overwrite) outside the module. Under elevated daemon privilege this allows privilege escalation. Default "use chroot = yes" is not exposed.
A flaw was found in rsync. An authenticated daemon peer can exploit an integer overflow vulnerability in the compressed-token decoder. By carefully manipulating the compressed-token, a malicious sender can trigger an overflow, leading to remote memory disclosure. This allows an attacker to leak sensitive process memory contents, including environment variables, passwords, and memory pointers, which significantly weakens Address Space Layout Randomization (ASLR) and can facilitate further exploitation.
A malicious client acting as the receiver of an rsync file transfer can trigger an out of bounds read of a heap based buffer, via a negative array index. The
A malicious client acting as the receiver of an rsync file transfer can trigger an out of bounds read of a heap based buffer, via a negative array index. The
malicious
rsync client requires at least read access to the remote rsync module in order to trigger the issue.
Last updated 2 June 2026
Last updated 22 May 2026
Last updated 2 June 2026
Last updated 2 June 2026
Rejected reason: REJECT DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2026-43618. Reason: This candidate is a duplicate of CVE-2026-43618. Notes: All CVE users should reference CVE-2026-43618 instead of this candidate.
Rejected reason: REJECT DO NOT USE THIS CANDIDATE NUMBER. ConsultIDs: CVE-2026-43619. Reason: This candidate is a duplicate of CVE-2026-43619. Notes: All CVE users should reference CVE-2026-43619 instead of this candidate.