USN-8804-1: OpenSSH vulnerabilities

USN-8804-1: OpenSSH vulnerabilities

https://ubuntu.com/security/notices/rss.xml / Tue, 09/22/2026 - 19:33
Florian Kohnhäuser discovered that OpenSSH incorrectly handled shell metacharacters in certain usernames. An attacker could possibly use this issue to execute arbitrary commands when certain non-default configurations were used, resulting in arbitrary code execution. This issue only affected Ubuntu 14.04 LTS. (CVE-2026-35386) Christos Papakonstantinou discovered that OpenSSH incorrectly handled ECDSA algorithm restrictions. An attacker could possibly use this issue to cause unintended ECDSA algorithms to be accepted, resulting in security restrictions being bypassed. (CVE-2026-35387) Vladimir Tokarev discovered that OpenSSH incorrectly handled certain principal restrictions in authorized_keys files. An attacker could possibly use this issue to bypass principal restrictions, resulting in unauthorized access. This issue only affected Ubuntu 14.04 LTS, Ubuntu 18.04 LTS, and Ubuntu 20.04 LTS. (CVE-2026-35414) It was discovered that OpenSSH incorrectly handled downloaded file paths when using sftp with an untrusted server. An attacker could possibly use this issue to write downloaded files outside the intended location, resulting in unauthorized file modification. (CVE-2026-59995) It was discovered that OpenSSH incorrectly handled command-line arguments in internal-sftp. An attacker could possibly use this issue to cause certain security-related arguments to be ignored, resulting in security restrictions being bypassed. (CVE-2026-59997) It was discovered that OpenSSH incorrectly handled GSSAPIStrictAcceptorCheck when used with Windows Active Directory. An attacker could possibly use this issue to bypass GSSAPI security restrictions, resulting in unauthorized access. (CVE-2026-59998) It was discovered that OpenSSH incorrectly handled forwarding restrictions when DisableForwarding and PermitTunnel were used together. An attacker could possibly use this issue to create tunnels despite forwarding being disabled, resulting in security restrictions being bypassed. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04 LTS. (CVE-2026-59999) It was discovered that OpenSSH incorrectly handled authentication attempt limits when using GSSAPI authentication. An attacker could possibly use this issue to consume excessive system resources, resulting in a denial of service. (CVE-2026-60000) It was discovered that OpenSSH did not always enforce the minimum authentication delay. An attacker could possibly use this issue to perform authentication attempts more rapidly than intended, resulting in weakened brute-force protections. This issue only affected Ubuntu 20.04 LTS. (CVE-2026-60001) It was discovered that OpenSSH incorrectly handled certain concurrent remote forwarding operations. An attacker could possibly use this issue to trigger a use-after-free, resulting in a denial of service or arbitrary code execution. (CVE-2026-73282)

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Kenya Education Network CERT(KENET-CERT) is a Cybersecurity Emergency Response Team and Co-ordination Center operated by the National Research and Education Network of Kenya. KENET-CERT coordination center promotes awareness on cybersecurity incidences as well as coordinates and assists member institutions in responding effectively to cyber security threats and incidences. KENET-CERT works closely with Kenya's National CIRT coordination center (CIRT/CC) as a sector CIRT for the academic institutions. KENET promotes use of ICT in Teaching, Learning and Research in Higher Education Institutions in Kenya. KENET aims to interconnect all the Universities, Tertiary and Research Institutions in Kenya by setting up a cost effective and sustainable private network with high speed access to the global Internet. KENET also facilitates electronic communication among students and faculties in member institutions, share learning and teaching resources by collaboration in Research and Development of Educational content.