Packages
- libssh - A tiny C SSH library
Details
It was discovered that libssh had a stack buffer overflow in its SFTP
server when constructing directory listing entries for long filenames. An
attacker could possibly use this issue to cause libssh to crash or execute
arbitrary code. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-15370)
It was discovered that libssh did not correctly handle SSH channel open
messages advertising a zero maximum packet size. An authenticated remote
attacker could possibly use this issue to cause libssh to consume excessive
CPU resources, leading to a denial of service. (CVE-2026-59843)
It was discovered that libssh did not correctly limit SFTP read request
lengths in its server implementation. An authenticated remote attacker
could possibly use this issue to cause libssh to allocate excessive memory,
leading to a denial of service. This issue only affected Ubuntu...
It was discovered that libssh had a stack buffer overflow in its SFTP
server when constructing directory listing entries for long filenames. An
attacker could possibly use this issue to cause libssh to crash or execute
arbitrary code. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-15370)
It was discovered that libssh did not correctly handle SSH channel open
messages advertising a zero maximum packet size. An authenticated remote
attacker could possibly use this issue to cause libssh to consume excessive
CPU resources, leading to a denial of service. (CVE-2026-59843)
It was discovered that libssh did not correctly limit SFTP read request
lengths in its server implementation. An authenticated remote attacker
could possibly use this issue to cause libssh to allocate excessive memory,
leading to a denial of service. This issue only affected Ubuntu 26.04 LTS.
(CVE-2026-59844)
It was discovered that libssh did not correctly handle ProxyCommand fork()
failures. A local attacker could possibly use this issue to cause a denial
of service. (CVE-2026-59845)
It was discovered that libssh did not correctly sanitize shell
metacharacters when expanding usernames in ProxyCommand strings. An
attacker could possibly use this issue to obtain sensitive information.
(CVE-2026-59846)
It was discovered that libssh had incorrect AES-GCM tag verification when
built with the OpenSSL backend. A machine-in-the-middle attacker could
possibly use this issue to modify encrypted traffic without detection.
(CVE-2026-59847)
It was discovered that libssh did not correctly handle SFTP server
responses for unknown request IDs. An attacker could possibly use this
issue to cause libssh to use excessive memory, leading to a denial of
service. (CVE-2026-59848)
It was discovered that libssh had logic errors in certificate-based
authentication that could cause clients to loop indefinitely when
certificates were rejected. An attacker could possibly use this issue to
cause a denial of service. This issue only affected Ubuntu 26.04 LTS.
(CVE-2026-59849)
It was discovered that libssh could invoke data callbacks on channels after
they had been closed. An attacker could possibly use this issue to cause
libssh to crash or execute arbitrary code. (CVE-2026-59850)
Update instructions
In general, a standard system update will make all the necessary changes.
Learn more about how to get the fixes.The problem can be corrected by updating your system to the following package versions:
| Ubuntu Release | Package Version | ||
|---|---|---|---|
| 26.04 LTS resolute | libssh-4 – 0.11.3-1ubuntu2.1 | ||
| 24.04 LTS noble | libssh-4 – 0.10.6-2ubuntu0.5 | ||
| 22.04 LTS jammy | libssh-4 – 0.9.6-2ubuntu0.22.04.8 | ||
Reduce your security exposure
Ubuntu Pro provides ten-year security coverage to 25,000+ packages in Main and Universe repositories, and it is free for up to five machines.