[slackware-security] libssh

New libssh packages are available for Slackware 15.0 and -current to fix security issues. Here are the details from the Slackware 15.0 ChangeLog: patches/packages/libssh-0.11.5-i586-1slack15.0.txz: Upgraded. This update fixes security issues: Stack buffer overflow in SFTP server longname...

Slackware Linux 15.0 / current libssh Multiple Vulnerabilities (SSA:2026-202-01)

The version of libssh installed on the remote host is prior to 0.11.5 / 0.12.1. It is, therefore, affected by multiple vulnerabilities as referenced in the SSA:2026-202-01 advisory. New libssh packages are available for Slackware 15.0 and -current to fix security issues. Tenable has extracted the...

libssh: libssh: information disclosure via ProxyCommand %r username expansion

A flaw was found in libssh. A malicious username expanded through %r in ProxyCommand handling can inject shell metacharacters, exposing environment variables and causing unintended shell behavior...

Important: Red Hat Security Advisory: Red Hat Hardened Images RPMs bug fix and enhancement update

An update for Red Hat Hardened Images RPMs is now available. This update includes the following RPMs: libssh: libssh-0.12.1-4.hum1 aarch64, x8664 libssh-config-0.12.1-4.hum1 noarch libssh-devel-0.12.1-4.hum1 aarch64, x8664 libssh-0.12.1-4.hum1.src src...

libssh: libssh: authentication bypass via missing GSSAPI principal check

A flaw was found in libssh. On servers with GSSAPIKeyExchange enabled, the gssapi-keyex path does not verify whether the authenticated Kerberos principal is authorized for the requested local user, allowing authenticated clients to log in as arbitrary users...

libssh: libssh: denial of service via automatic certificate authentication loop

A flaw was found in libssh. Logic errors in automatic certificate-based public key authentication can cause libssh clients to loop indefinitely when configured certificates are missing or repeatedly rejected by a server, leading to denial of service...

libssh: libssh: denial of service via zero advertised channel packet size

A flaw was found in libssh. A remote authenticated peer can advertise a zero maximum packet size in SSHMSGCHANNELOPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service...

libssh: libssh: denial of service via oversized SFTP read length

A flaw was found in libssh. A remote authenticated client can issue SSHFXPREAD requests with an arbitrarily large length, causing a libssh SFTP server to allocate excessive memory and potentially exhaust it through repeated requests...

libssh: libssh: information disclosure via short GSSAPI Curve25519 public key

A flaw was found in libssh. During server-side GSSAPI key exchange, a client-supplied Curve25519 public key shorter than the expected length is copied without proper length validation, leading to an out-of-bounds heap read. This could allow a remote unauthenticated attacker to disclose small...

libssh: libssh: denial of service via SFTP responses with unknown request IDs

A flaw was found in libssh. A malicious SFTP server can send responses for unknown request IDs that libssh clients keep queued indefinitely, causing unbounded memory growth and client-side denial of service...

libssh: libssh: integrity downgrade via OpenSSL AES-GCM tag verification

A flaw was found in libssh. Incorrect AES-GCM finalization checks in builds using the OpenSSL backend can effectively remove integrity protection, allowing an in-path attacker to modify plaintext on the wire without detection...

libssh: libssh: denial of service via unchecked ProxyCommand fork() failure

A flaw was found in libssh. When ProxyCommand is used, an unchecked fork failure can be stored as process ID -1; during cleanup, signals may then be sent across the caller's accessible process tree, leading to local denial of service...

CVE-2026-59849

A flaw was found in libssh. Logic errors in automatic certificate-based public key authentication can cause libssh clients to loop indefinitely when configured certificates are missing or repeatedly rejected by a server, leading to denial of service...

CVE-2026-59850

A flaw was found in libssh. If data packets are processed after a channel is closed, channel data callbacks can be invoked after the associated data has already been freed, leading to crashes or possible use-after-free conditions...

UBUNTU-CVE-2026-59849

A flaw was found in libssh. Logic errors in automatic certificate-based public key authentication can cause libssh clients to loop indefinitely when configured certificates are missing or repeatedly rejected by a server, leading to denial of service...

UBUNTU-CVE-2026-59851

A flaw was found in libssh. On servers with GSSAPIKeyExchange enabled, the gssapi-keyex path does not verify whether the authenticated Kerberos principal is authorized for the requested local user, allowing authenticated clients to log in as arbitrary users...

UBUNTU-CVE-2026-59850

A flaw was found in libssh. If data packets are processed after a channel is closed, channel data callbacks can be invoked after the associated data has already been freed, leading to crashes or possible use-after-free conditions...

Security Bulletin: Vulnerabilities in multiple components affect IBM SAN Volume Controller, IBM Spectrum Virtualize and IBM FlashSystem products

Summary Vulnerabilities in openssh, libssh, kernel and gnutls components affect IBM Storage Virtualize products and could cause confidentiality, integrity and availability impacts. CVE-2026-35387 CVE-2026-35414 CVE-2025-5372 CVE-2022-50865 CVE-2025-39971 CVE-2025-14831. Vulnerability Details...

CVE-2026-59851

A vulnerability in libssh affects servers with GSSAPIKeyExchange enabled. The gssapi-keyex path does not verify that the authenticated Kerberos principal is authorized for the requested local user, enabling authenticated clients to log in as arbitrary users. This is reported across multiple sourc...

CVE-2026-59851

A flaw was found in libssh. On servers with GSSAPIKeyExchange enabled, the gssapi-keyex path does not verify whether the authenticated Kerberos principal is authorized for the requested local user, allowing authenticated clients to log in as arbitrary users...