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  • 1.  libssh2 security vulnerability fix

    Posted 16 hours ago

    libssh2-1.11.1-2.aix7.1.ppc.rpm is now available in AIX Toolbox.

    This version of libssh2 has fixes for the following security vulnerabilities.

    CVE-2025-15661
    CVE-2026-55199
    CVE-2026-55200
    CVE-2026-7598


    You can use DNF to update to this version of package from the AIX Toolbox repository.



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    Sumitra Dawn
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  • 2.  RE: libssh2 security vulnerability fix

    Posted 9 hours ago

    Hallo team,

    thank you for the update. It is great to see that some issues have been fixed. 

    However, IIRC the original warning for libssh2 did also mention:

    CVE-2026-15370 - 7.3 - During SFTP server directory listing, the longname field is constructed with unsafe concatenation into a fixed-size stack buffer. When a client causes the server to list attacker-controlled filenames, sufficiently long names can overflow that stack buffer and may lead to crashes or possible code execution on the server. 
    CVE-2026-59842 - 5.3 - 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 amounts of server memory. ,
    CVE-2026-59843 - 6.5 - A remote authenticated peer can advertise a zero maximum packet size in SSH_MSG_CHANNEL_OPEN, causing later channel writes to loop indefinitely and consume CPU, leading to denial of service.
    CVE-2026-59844 - 6.5 - A remote authenticated client can issue SSH_FXP_READ requests with an arbitrarily large length, causing a libssh SFTP server to allocate excessive memory and potentially exhaust it through repeated requests. ,
    CVE-2026-59845 - 5.9 - 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-2026-59846 - 3.9 - A malicious username expanded through %r in ProxyCommand handling can inject shell metacharacters, exposing environment variables and causing unintended shell behavior. ,
    CVE-2026-59847 - 7.5 - 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. ,
    CVE-2026-59848 - 5.3 - 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. ,
    CVE-2026-59849 - 7.5 -  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 - 7.5 -  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. ,
    CVE-2026-59851 - 8.8 - 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. 

    Can you tell whether these CVE have also been fixed with libssh2-1.11.1-2.ppc or would this require another update?

    Thanks and regards,

    Andreas Schulze



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    Andreas Schulze
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