Aggregates CVE and security vulnerability intelligence across all libssh-related products, including CVSS, EPSS, publication dates, and vulnerability intelligence data.
Disclosed issues often relate to vendor risk memory corruption, vendor risk buffer overflow, and vendor risk path handling; exposure may include vendor impact application crash in vendor surface software deployment contexts.
| CVE | Summary | Source | Max CVSS | EPSS % | Published | Updated |
|---|---|---|---|---|---|---|
| CVE-2025-14821 | A flaw was found in libssh. This vulnerability allows local man-in-the-middle attacks, security downgrades of SSH (Secure Shell) connections, and manipulation of trusted host information, posing a significant risk to the confidentiality, integrity, and availability of SSH communications via an insecure default configuration on Windows systems where the library automatically loads configuration files from the C:\etc directory, which can be created and modified by unprivileged local users. | [email protected] | 7.8 | 0.01% | 2026-04-07 | 2026-04-29 |
| CVE-2026-0968 | A flaw was found in libssh in which a malicious SFTP (SSH File Transfer Protocol) server can exploit this by sending a malformed 'longname' field within an `SSH_FXP_NAME` message during a file listing operation. This missing null check can lead to reading beyond allocated memory on the heap. This can cause unexpected behavior or lead to a denial of service (DoS) due to application crashes. | [email protected] | 3.1 | 0.04% | 2026-03-26 | 2026-05-19 |
| CVE-2026-0967 | A flaw was found in libssh. A remote attacker, by controlling client configuration files or known_hosts files, could craft specific hostnames that when processed by the `match_pattern()` function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion, resulting in a Denial of Service (DoS) for the client. | [email protected] | 5.5 | 0.03% | 2026-03-26 | 2026-05-19 |
| CVE-2026-0966 | A flaw was found in libssh. The API function `ssh_get_hexa()` is vulnerable to a denial of service when processing zero-length input. This can be exploited remotely by an attacker during GSSAPI (Generic Security Service Application Program Interface) authentication if the server's logging verbosity is set to `SSH_LOG_PACKET (3)` or higher. Successful exploitation could lead to a self-Denial of Service of the per-connection daemon process. | [email protected] | 8.2 | 0.07% | 2026-03-26 | 2026-05-19 |
| CVE-2026-0965 | A flaw was found in libssh where it can attempt to open arbitrary files during configuration parsing. A local attacker can exploit this by providing a malicious configuration file or when the system is misconfigured. This vulnerability could lead to a Denial of Service (DoS) by causing the system to try and access dangerous files, such as block devices or large system files, which can disrupt normal operations. | [email protected] | 3.3 | 0.01% | 2026-03-26 | 2026-05-19 |
| CVE-2026-0964 | A malicious SCP server can send unexpected paths that could make the client application override local files outside of working directory. This could be misused to create malicious executable or configuration files and make the user execute them under specific consequences. This is the same issue as in OpenSSH, tracked as CVE-2019-6111. | [email protected] | 6.3 | 0.04% | 2026-03-26 | 2026-05-19 |
| CVE-2026-3731 | A weakness has been identified in libssh up to 0.11.3. The impacted element is the function sftp_extensions_get_name/sftp_extensions_get_data of the file src/sftp.c of the component SFTP Extension Name Handler. Executing a manipulation of the argument idx can lead to out-of-bounds read. The attack may be performed from remote. Upgrading to version 0.11.4 and 0.12.0 is sufficient to resolve this issue. This patch is called 855a0853ad3abd4a6cd85ce06fce6d8d4c7a0b60. You should upgrade the affected | [email protected] | 6.9 | 0.04% | 2026-03-08 | 2026-03-12 |
| CVE-2025-5449 | A flaw was found in the SFTP server message decoding logic of libssh. The issue occurs due to an incorrect packet length check that allows an integer overflow when handling large payload sizes on 32-bit systems. This issue leads to failed memory allocation and causes the server process to crash, resulting in a denial of service. | [email protected] | 6.5 | 0.52% | 2025-07-25 | 2026-01-08 |
| CVE-2025-8114 | A flaw was found in libssh, a library that implements the SSH protocol. When calculating the session ID during the key exchange (KEX) process, an allocation failure in cryptographic functions may lead to a NULL pointer dereference. This issue can cause the client or server to crash. | [email protected] | 4.7 | 0.16% | 2025-07-24 | 2026-05-19 |
| CVE-2025-5987 | A flaw was found in libssh when using the ChaCha20 cipher with the OpenSSL library. If an attacker manages to exhaust the heap space, this error is not detected and may lead to libssh using a partially initialized cipher context. This occurs because the OpenSSL error code returned aliases with the SSH_OK code, resulting in libssh not properly detecting the error returned by the OpenSSL library. This issue can lead to undefined behavior, including compromised data confidentiality and integrity or | [email protected] | 8.1 | 1.23% | 2025-07-07 | 2026-03-20 |
| CVE-2025-5351 | A flaw was found in the key export functionality of libssh. The issue occurs in the internal function responsible for converting cryptographic keys into serialized formats. During error handling, a memory structure is freed but not cleared, leading to a potential double free issue if an additional failure occurs later in the function. This condition may result in heap corruption or application instability in low-memory scenarios, posing a risk to system reliability where key export operations ar | [email protected] | 6.5 | 0.58% | 2025-07-04 | 2026-05-19 |
| CVE-2025-5372 | A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the ssh_kdf() function responsible for key derivation. Due to inconsistent interpretation of return values where OpenSSL uses 0 to indicate failure and libssh uses 0 for success—the function may mistakenly return a success status even when key derivation fails. This results in uninitialized cryptographic key buffers being used in subsequent communication, potentially compromising SSH sessions' confide | [email protected] | 5.0 | 0.30% | 2025-07-04 | 2026-06-15 |
| CVE-2025-5318 | A flaw was found in the libssh library in versions less than 0.11.2. An out-of-bounds read can be triggered in the sftp_handle function due to an incorrect comparison check that permits the function to access memory beyond the valid handle list and to return an invalid pointer, which is used in further processing. This vulnerability allows an authenticated remote attacker to potentially read unintended memory regions, exposing sensitive information or affect service behavior. | [email protected] | 8.1 | 0.18% | 2025-06-24 | 2026-02-27 |
| CVE-2023-6004 | A flaw was found in libssh. By utilizing the ProxyCommand or ProxyJump feature, users can exploit unchecked hostname syntax on the client. This issue may allow an attacker to inject malicious code into the command of the features mentioned through the hostname parameter. | [email protected] | 4.8 | 0.05% | 2024-01-03 | 2025-11-04 |
| CVE-2023-6918 | A flaw was found in the libssh implements abstract layer for message digest (MD) operations implemented by different supported crypto backends. The return values from these were not properly checked, which could cause low-memory situations failures, NULL dereferences, crashes, or usage of the uninitialized memory as an input for the KDF. In this case, non-matching keys will result in decryption/integrity failures, terminating the connection. | [email protected] | 3.7 | 0.37% | 2023-12-19 | 2025-02-15 |
| CVE-2023-48795 | The SSH transport protocol with certain OpenSSH extensions, found in OpenSSH before 9.6 and other products, allows remote attackers to bypass integrity checks such that some packets are omitted (from the extension negotiation message), and a client and server may consequently end up with a connection for which some security features have been downgraded or disabled, aka a Terrapin attack. This occurs because the SSH Binary Packet Protocol (BPP), implemented by these extensions, mishandles the ha | [email protected] | 5.9 | 51.66% | 2023-12-18 | 2026-05-12 |
| CVE-2023-3603 | A missing allocation check in sftp server processing read requests may cause a NULL dereference on low-memory conditions. The malicious client can request up to 4GB SFTP reads, causing allocation of up to 4GB buffers, which was not being checked for failure. This will likely crash the authenticated user's sftp server connection (if implemented as forking as recommended). For thread-based servers, this might also cause DoS for legitimate users. Given this code is not in any released versions, | [email protected] | 3.1 | 0.12% | 2023-07-21 | 2024-11-21 |
| CVE-2023-2283 | A vulnerability was found in libssh, where the authentication check of the connecting client can be bypassed in the`pki_verify_data_signature` function in memory allocation problems. This issue may happen if there is insufficient memory or the memory usage is limited. The problem is caused by the return value `rc,` which is initialized to SSH_ERROR and later rewritten to save the return value of the function call `pki_key_check_hash_compatible.` The value of the variable is not changed between t | [email protected] | 6.5 | 0.20% | 2023-05-26 | 2025-11-03 |
| CVE-2023-1667 | A NULL pointer dereference was found In libssh during re-keying with algorithm guessing. This issue may allow an authenticated client to cause a denial of service. | [email protected] | 6.5 | 1.27% | 2023-05-26 | 2024-11-21 |
| CVE-2021-3634 | A flaw has been found in libssh in versions prior to 0.9.6. The SSH protocol keeps track of two shared secrets during the lifetime of the session. One of them is called secret_hash and the other session_id. Initially, both of them are the same, but after key re-exchange, previous session_id is kept and used as an input to new secret_hash. Historically, both of these buffers had shared length variable, which worked as long as these buffers were same. But the key re-exchange operation can also cha | [email protected] | 6.5 | 0.12% | 2021-08-31 | 2024-11-21 |