RHSA-2026:20610 Red Hat Security Advisory: libssh security update

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libssh: Incorrect Return Code Handling in ssh_kdf() in libssh

A flaw was found in libssh versions built with OpenSSL versions older than 3.0, specifically in the sshkdf 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 mistakenl...

Moderate: Red Hat Security Advisory: libssh security update

An update for libssh is now available for Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions and Red Hat Enterprise Linux 8.8 Telecommunications Update Service. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring Syste...

curl: CVE-2026-9547: SSH improper host validation

Hi all, We've found an issue in lib/vssh/libssh.c where the libssh backend maps SSHKNOWNHOSTSOTHER to CURLKHMATCHMISSING instead of CURLKHMATCHMISMATCH. libssh documents SSHKNOWNHOSTSOTHER as "The server gave us a key of a type while we had another type recorded. It is a possible attack."...

RHSA-2026:18683 Red Hat Security Advisory: libssh security update

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Astra Linux – Vulnerability in libssh

A flaw was discovered in the abstract layer of the libssh library responsible for message digest MD operations, which is implemented by different supported crypto backends. The return values from these operations were not properly checked, which could lead to low-memory situations, NULL...

Astra Linux – Vulnerability in libssh

In libssh 0.9.4, there is a NULL pointer dereferencing in tftpserver.c if sshbuffernew returns NULL...

Astra Linux – Vulnerability in libssh

A flaw was discovered in the libssh API function sshscpnew, in versions prior to 0.9.3 and prior to 0.8.8. When the libssh SCP client connects to a server, the scp command, which includes a path provided by the user, is executed on the server side. If the library is used in a way that allows user...

Astra Linux – Vulnerability in libssh

A flaw was discovered in libssh. By using the ProxyCommand or ProxyJump feature, users can exploit unvalidated hostname syntax on the client side. This issue may allow an attacker to inject malicious code into the commands related to these features via the hostname parameter...

Astra Linux – Vulnerability in libssh

A NULL pointer dereference was detected in libssh during re-keying with algorithm guessing. This issue may allow an authenticated client to cause a denial of service...

Advisory ROSA-SA-2026-3282

software: libssh 0.9.8 OS: ROSA-CHROME unaffected versions = libssh-0.9.8-5 affected versions libssh-0.9.8-5 CVE-ID: CVE-2026-0965 BDU-ID: None CVE-Crit: LOW CVE-DESC.: A vulnerability in libssh is related to the ability to open arbitrary files during configuration parsing. A local attacker could...

Advisory ROSA-SA-2026-3275

software: libssh 0.9.8 OS: ROSA-CHROME unaffected versions = libssh-0.9.8-4 affected versions libssh-0.9.8-4 CVE-ID: CVE-2026-3731 BDU-ID: None CVE-Crit: MEDIUM CVE-DESC.: A read outside allocated buffer vulnerability in the SFTP Extension Name Handler component of the libssh library allows a...

libssh: Write beyond bounds in binary to base64 conversion functions

There's a vulnerability in the libssh package where when a libssh consumer passes in an unexpectedly large input buffer to sshgetfingerprinthash function. In such cases the bintobase64 function can experience an integer overflow leading to a memory under allocation, when that happens it's possibl...

libssh: Double Free Vulnerability in libssh Key Export Functions

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 additiona...

libssh: libssh: Denial of Service via improper configuration file handling

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 t...

libssh: NULL Pointer Dereference in libssh KEX Session ID Calculation

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...

libssh: Memory Exhaustion via Repeated Key Exchange in libssh

A flaw was found in libssh's handling of key exchange KEX processes when a client repeatedly sends incorrect KEX guesses. The library fails to free memory during these rekey operations, which can gradually exhaust system memory. This issue can lead to crashes on the client side, particularly when...

Moderate: Red Hat Security Advisory: libssh security update

An update for libssh is now available for Red Hat Enterprise Linux 9. Red Hat Product Security has rated this update as having a security impact of Moderate. A Common Vulnerability Scoring System CVSS base score, which gives a detailed severity rating, is available for each vulnerability from the...

libssh: libssh: Denial of Service via inefficient regular expression processing

A flaw was found in libssh. A remote attacker, by controlling client configuration files or knownhosts files, could craft specific hostnames that when processed by the matchpattern function can lead to inefficient regular expression backtracking. This can cause timeouts and resource exhaustion,...

libssh: libssh: Denial of Service via zero-length input in ssh_get_hexa()

A flaw was found in libssh. The API function sshgethexa 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 se...