Ships with Ubuntu 18.04
OpenSSH 7.6p1 vulnerabilities
OpenSSH 7.6p1 ships with Ubuntu 18.04. The US National Vulnerability Database lists 40 vulnerabilities for this version, 1 of them critical. OpenSSH fixes flaws only in its newest release. Distributions backport those fixes while they are supported and stop at end of life.
- 40known vulnerabilities
- 1critical
- 4high
- 0exploited in the wild
Is OpenSSH 7.6p1 affected?
| Vulnerability | CVE | OpenSSH 7.6p1 |
|---|---|---|
| regreSSHion | CVE-2024-6387 | Not affected |
| Terrapin | CVE-2023-48795 | Affected |
For the upstream version, according to the US National Vulnerability Database. Your distribution may have backported a fix before its end of life.
What you can do
Keep OpenSSH 7.6p1, patched
We backport the security fixes to the OpenSSH package of your distribution, built and tested before delivery. A fix for a new vulnerability arrives within 48 hours of your order, or within 24 hours with priority delivery.
Upgrade
Move to a supported distribution and its newer OpenSSH, once your servers can make the jump. Our fixes keep you safe while you plan it.
Assess first
Our assessment shows which vulnerabilities are real on your servers, what else is past end of life, and the remediation plan.
All 40 known vulnerabilities in OpenSSH 7.6p1
US National Vulnerability Database, 28 October 2026, highest score first. Fixed in: the first upstream release with the fix, where NVD records it. Exploited: listed in the CISA catalogue of known exploited vulnerabilities. Distribution builds may already include fixes for some of them.
| CVE | Score | Severity | Published | Fixed in | Description |
|---|---|---|---|---|---|
| CVE-2023-38408 | 9.8 | Critical | 2023-07-20 | 9.3 | The PKCS#11 feature in ssh-agent in OpenSSH before 9.3p2 has an insufficiently trustworthy search path, leading to remote code execution if an agent is forwarded to an attacker-controlled system. (Code in /usr/lib is not necessarily safe for loading into ssh-agent.) NOTE: this issue exists because of an incomplete fix for CVE-2016-10009. |
| CVE-2026-60002 | 7.7 | High | 2026-07-08 | 10.4 | ssh in OpenSSH before 10.4 can have a use-after-free when a server changes its host key during a key re-exchange. (This outcome occurs only on the client side.) |
| CVE-2026-35385 | 7.5 | High | 2026-04-02 | 10.3 | In OpenSSH before 10.3, a file downloaded by scp may be installed setuid or setgid, an outcome contrary to some users' expectations, if the download is performed as root with -O (legacy scp protocol) and without -p (preserve mode). |
| CVE-2020-15778 | 7.4 | High | 2020-07-24 | 8.3 | scp in OpenSSH through 8.3p1 allows command injection in the scp.c toremote function, as demonstrated by backtick characters in the destination argument. NOTE: the vendor reportedly has stated that they intentionally omit validation of "anomalous argument transfers" because that could "stand a great chance of breaking existing workflows." |
| CVE-2021-41617 | 7.0 | High | 2021-09-26 | 8.8 | sshd in OpenSSH 6.2 through 8.x before 8.8, when certain non-default configurations are used, allows privilege escalation because supplemental groups are not initialized as expected. Helper programs for AuthorizedKeysCommand and AuthorizedPrincipalsCommand may run with privileges associated with group memberships of the sshd process, if the configuration specifies running the command as a different user. |
| CVE-2019-6109 | 6.8 | Medium | 2019-01-31 | n/a | An issue was discovered in OpenSSH 7.9. Due to missing character encoding in the progress display, a malicious server (or Man-in-The-Middle attacker) can employ crafted object names to manipulate the client output, e.g., by using ANSI control codes to hide additional files being transferred. This affects refresh_progress_meter() in progressmeter.c. |
| CVE-2019-6110 | 6.8 | Medium | 2019-01-31 | n/a | In OpenSSH 7.9, due to accepting and displaying arbitrary stderr output from the server, a malicious server (or Man-in-The-Middle attacker) can manipulate the client output, for example to use ANSI control codes to hide additional files being transferred. |
| CVE-2025-26465 | 6.8 | Medium | 2025-02-18 | n/a | A vulnerability was found in OpenSSH when the VerifyHostKeyDNS option is enabled. A machine-in-the-middle attack can be performed by a malicious machine impersonating a legit server. This issue occurs due to how OpenSSH mishandles error codes in specific conditions when verifying the host key. For an attack to be considered successful, the attacker needs to manage to exhaust the client's memory resource first, turning the attack complexity high. |
| CVE-2023-51385 | 6.5 | Medium | 2023-12-18 | 9.6 | In ssh in OpenSSH before 9.6, OS command injection might occur if a user name or host name has shell metacharacters, and this name is referenced by an expansion token in certain situations. For example, an untrusted Git repository can have a submodule with shell metacharacters in a user name or host name. |
| CVE-2026-106585 | 6.5 | Medium | 2026-10-06 | 10.6 | In sshd and ssh in OpenSSH before 10.6, there is no check for whether the maximum packet length is exceeded during decompression of highly compressed data. |
| CVE-2026-60001 | 6.5 | Medium | 2026-07-08 | 10.4 | sshd in OpenSSH before 10.4 does not always honor the minimum authentication delay. |
| CVE-2019-6111 | 5.9 | Medium | 2019-01-31 | n/a | An issue was discovered in OpenSSH 7.9. Due to the scp implementation being derived from 1983 rcp, the server chooses which files/directories are sent to the client. However, the scp client only performs cursory validation of the object name returned (only directory traversal attacks are prevented). A malicious scp server (or Man-in-The-Middle attacker) can overwrite arbitrary files in the scp client target directory. If recursive operation (-r) is performed, the server can manipulate subdirectories as well (for example, to overwrite the .ssh/authorized_keys file). |
| CVE-2020-14145 | 5.9 | Medium | 2020-06-29 | 8.4 | The client side in OpenSSH 5.7 through 8.4 has an Observable Discrepancy leading to an information leak in the algorithm negotiation. This allows man-in-the-middle attackers to target initial connection attempts (where no host key for the server has been cached by the client). NOTE: some reports state that 8.5 and 8.6 are also affected. |
| CVE-2023-48795 | 5.9 | Medium | 2023-12-18 | 9.6 | 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 handshake phase and mishandles use of sequence numbers. For example, there is an effective attack against SSH's use of ChaCha20-Poly1305 (and CBC with Encrypt-then-MAC). The bypass occurs in chacha20-poly1305@openssh.com and (if CBC is used) the -etm@openssh.com MAC algorithms. This also affects Maverick Synergy Java SSH API before 3.1.0-SNAPSHOT, Dropbear through 2022.83, Ssh before 5.1.1 in Erlang/OTP, PuTTY before 0.80, AsyncSSH before 2.14.2, golang.org/x/crypto before 0.17.0, libssh before 0.10.6, libssh2 through 1.11.0, Thorn Tech SFTP Gateway before 3.4.6, Tera Term before 5.1, Paramiko before 3.4.0, jsch before 0.2.15, SFTPGo before 2.5.6, Netgate pfSense Plus through 23.09.1, Netgate pfSense CE through 2.7.2, HPN-SSH through 18.2.0, ProFTPD before 1.3.8b (and before 1.3.9rc2), ORYX CycloneSSH before 2.3.4, NetSarang XShell 7 before Build 0144, CrushFTP before 10.6.0, ConnectBot SSH library before 2.2.22, Apache MINA sshd through 2.11.0, sshj through 0.37.0, TinySSH through 20230101, trilead-ssh2 6401, LANCOM LCOS and LANconfig, FileZilla before 3.66.4, Nova before 11.8, PKIX-SSH before 14.4, SecureCRT before 9.4.3, Transmit5 before 5.10.4, Win32-OpenSSH before 9.5.0.0p1-Beta, WinSCP before 6.2.2, Bitvise SSH Server before 9.32, Bitvise SSH Client before 9.33, KiTTY through 0.76.1.13, the net-ssh gem 7.2.0 for Ruby, the mscdex ssh2 module before 1.15.0 for Node.js, the thrussh library before 0.35.1 for Rust, and the Russh crate before 0.40.2 for Rust. |
| CVE-2026-59999 | 5.9 | Medium | 2026-07-08 | 10.4 | In sshd in OpenSSH before 10.4, DisableForwarding=yes was supposed to take precedence over PermitTunnel=yes, but did not. |
| CVE-2016-20012 | 5.3 | Medium | 2021-09-15 | n/a | OpenSSH through 8.7 allows remote attackers, who have a suspicion that a certain combination of username and public key is known to an SSH server, to test whether this suspicion is correct. This occurs because a challenge is sent only when that combination could be valid for a login session. NOTE: the vendor does not recognize user enumeration as a vulnerability for this product |
| CVE-2018-15473 | 5.3 | Medium | 2018-08-17 | n/a | OpenSSH through 7.7 is prone to a user enumeration vulnerability due to not delaying bailout for an invalid authenticating user until after the packet containing the request has been fully parsed, related to auth2-gss.c, auth2-hostbased.c, and auth2-pubkey.c. |
| CVE-2018-15919 | 5.3 | Medium | 2018-08-28 | n/a | Remotely observable behaviour in auth-gss2.c in OpenSSH through 7.8 could be used by remote attackers to detect existence of users on a target system when GSS2 is in use. NOTE: the discoverer states 'We understand that the OpenSSH developers do not want to treat such a username enumeration (or "oracle") as a vulnerability.' |
| CVE-2018-20685 | 5.3 | Medium | 2019-01-10 | n/a | In OpenSSH 7.9, scp.c in the scp client allows remote SSH servers to bypass intended access restrictions via the filename of . or an empty filename. The impact is modifying the permissions of the target directory on the client side. |
| CVE-2026-59998 | 4.8 | Medium | 2026-07-08 | 10.4 | sshd in OpenSSH before 10.4 has an undocumented security-relevant behavior: GSSAPIStrictAcceptorCheck has no value if the server is in Windows Active Directory. |
| CVE-2026-73282 | 4.8 | Medium | 2026-08-11 | 10.5 | In ssh in OpenSSH before 10.5, a use-after-free for realloc data can occur if a certain pair of remote-forwarding operations are concurrent. |
| CVE-2025-32728 | 4.3 | Medium | 2025-04-10 | 10.0 | In sshd in OpenSSH before 10.0, the DisableForwarding directive does not adhere to the documentation stating that it disables X11 and agent forwarding. |
| CVE-2026-106552 | 4.2 | Medium | 2026-10-06 | 10.6 | In sftp in OpenSSH before 10.6, a server can trigger directory traversal (causing files to be written to unintended locations) during a recursive copy operation. |
| CVE-2026-35414 | 4.2 | Medium | 2026-04-02 | 10.3 | OpenSSH before 10.3 mishandles the authorized_keys principals option in uncommon scenarios involving a principals list in conjunction with a Certificate Authority that makes certain use of comma characters. |
| CVE-2026-59995 | 4.2 | Medium | 2026-07-08 | 10.4 | sftp in OpenSSH before 10.4 does not properly constrain the location of downloaded files when "sftp server:/path ." is used with an attacker-controlled server. |
| CVE-2026-59996 | 4.2 | Medium | 2026-07-08 | 10.4 | scp in OpenSSH before 10.4 may place a file in the parent directory of an intended directory when the copy occurs between two remote destinations. |
| CVE-2026-59997 | 4.2 | Medium | 2026-07-08 | 10.4 | internal-sftp in sshd in OpenSSH before 10.4 recognizes only the first 9 command-line arguments, which can be important if a later command-line argument would have helped to ensure the intended security properties of an SFTP connection. |
| CVE-2021-36368 | 3.7 | Low | 2022-03-13 | 8.9 | An issue was discovered in OpenSSH before 8.9. If a client is using public-key authentication with agent forwarding but without -oLogLevel=verbose, and an attacker has silently modified the server to support the None authentication option, then the user cannot determine whether FIDO authentication is going to confirm that the user wishes to connect to that server, or that the user wishes to allow that server to connect to a different server on the user's behalf. NOTE: the vendor's position is "this is not an authentication bypass, since nothing is being bypassed. |
| CVE-2026-106582 | 3.7 | Low | 2026-10-06 | 10.6 | In sshd and ssh in OpenSSH before 10.6, an LZ77 dictionary coder can be used even though this is contraindicated by the arXiv 2609.07709 "Crossing the Streams" findings. |
| CVE-2026-60000 | 3.7 | Low | 2026-07-08 | 10.4 | sshd in OpenSSH before 10.4 allows remote attackers to cause a denial of service (resource consumption from excessive authentication attempts) because MaxAuthTries was mishandled for GSSAPIAuthentication. |
| CVE-2026-106587 | 3.6 | Low | 2026-10-06 | 10.6 | In sshd in OpenSSH before 10.6, the value "none" for a configuration option is sometimes interpreted as a filename but was intended to mean that a feature is disabled. |
| CVE-2026-73281 | 3.5 | Low | 2026-08-11 | 10.5 | In ssh-agent in OpenSSH before 10.5, some operations can occur remotely but were intended to occur only locally, including operations that add tokens or use keys. This is caused by misinteraction between agent locking and the session-bind@openssh.com extension. |
| CVE-2026-35387 | 3.1 | Low | 2026-04-02 | 10.3 | OpenSSH before 10.3 can use unintended ECDSA algorithms. Listing of any ECDSA algorithm in PubkeyAcceptedAlgorithms or HostbasedAcceptedAlgorithms is misinterpreted to mean all ECDSA algorithms. |
| CVE-2026-106583 | 2.5 | Low | 2026-10-07 | 10.6 | In ssh in OpenSSH before 10.6, a $ or \ character can occur in a command-line username, leading to injection. |
| CVE-2026-106584 | 2.5 | Low | 2026-10-06 | 10.6 | In ssh-keygen in OpenSSH before 10.6, certificates could have incorrect expiration times because of Daylight Saving mishandling. There can be a slightly more severe effect on users in certain Antarctic locations. |
| CVE-2026-106586 | 2.5 | Low | 2026-10-06 | 10.6 | In sshd in OpenSSH before 10.6, the restrict keyword (in authorized_keys) was supposed to be applicable to tunnel forwarding but was not, a different vulnerability than CVE-2026-73283. |
| CVE-2026-35388 | 2.5 | Low | 2026-04-02 | 10.3 | OpenSSH before 10.3 omits connection multiplexing confirmation for proxy-mode multiplexing sessions. |
| CVE-2026-73283 | 2.5 | Low | 2026-08-11 | 10.5 | In sshd in OpenSSH before 10.5, the restrict keyword (in authorized_keys) was supposed to be applicable to tunnel forwarding but was not. |
| CVE-2026-106553 | 2.2 | Low | 2026-10-06 | 10.6 | In sshd in OpenSSH before 10.6, credentials can incorrectly persist after failure of a GSSAPIAuthentication authentication attempt. |
| CVE-2026-106555 | 2.2 | Low | 2026-10-06 | 10.6 | In sshd in OpenSSH before 10.6, GSSAPIAuthentication authentication state can incorrectly be persisted across authentication attempts. |