ESB-2026.4415

=========================================================================== AUSCERT External Security Bulletin Redistribution ESB-2026.4415 USN-8222-1: OpenSSH vulnerabilities 30 April 2026 =========================================================================== AUSCERT Security Bulletin Summary --------------------------------- Product: OpenSSH Publisher: Ubuntu Operating System: Ubuntu Resolution: Patch/Upgrade CVE Names: CVE-2026-35385 CVE-2026-35386 CVE-2026-35387 CVE-2026-35388 CVE-2026-35414 Original Bulletin: https://ubuntu.com/security/notices/USN-8222-1 Comment: CVSS (Max): 7.5 CVE-2026-35385 (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H) CVSS Source: Ubuntu Calculator: https://www.first.org/cvss/calculator/3.1#CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H EPSS (Max): 0.0% (11th) CVE-2026-35385 2026-04-29 - --------------------------BEGIN INCLUDED TEXT-------------------- USN-8222-1: OpenSSH vulnerabilities Publication date 29 April 2026 Overview Several security issues were fixed in OpenSSH. Releases 26.04 LTS 25.10 24.04 LTS 22.04 LTS --------------------------------------------------------------------------------- Open side navigation Packages o openssh - secure shell (SSH) for secure access to remote machines Details Christos Papakonstantinou discovered that the OpenSSH scp tool incorrectly handled the legacy scp protocol (-O) option. This could result in certain files being installed setuid or setgid, contrary to expectations. ( CVE-2026-35385 ) Florian Kohnhauser discovered that OpenSSH incorrectly handled shell metacharacters in usernames within a command line. When untrusted usernames and non-default configurations using % in ssh_config are being used, an attacker could possibly use this issue to execute arbitrary code. ( CVE-2026-35386 ) Christos Papakonstantinou discovered that OpenSSH incorrectly handled parsing the PubkeyAcceptedAlgorithms and HostbasedAcceptedAlgorithms options. This could result in unintended ECDSA algorithms being used, contrary to expectations. ( CVE-2026-35387 ) Michalis Vasileiadis discovered that OpenSSH incorrectly handled proxy-mode multiplexing sessions. This could result in no confirmation being asked, contrary to expectations. ( CVE-2026-35388 ) Vladimir Tokarev discovered that OpenSSH incorrectly handled certificates with the principal name containing a comma character when using user-trusted CA keys in authorized_keys and an authorized_keys principals=" option that lists more than one principal. This could result in inappropriate principal matching, contrary to expectations. ( CVE-2026-35414 ) --------------------------------------------------------------------------------- Update instructions The problem can be corrected by updating your system to the following package versions: Ubuntu Release Package Version 26.04 LTS resolute openssh-client - 1:10.2p1-2ubuntu3.2 openssh-server - 1:10.2p1-2ubuntu3.2 25.10 questing openssh-client - 1:10.0p1-5ubuntu5.4 openssh-server - 1:10.0p1-5ubuntu5.4 24.04 LTS noble openssh-client - 1:9.6p1-3ubuntu13.16 openssh-server - 1:9.6p1-3ubuntu13.16 22.04 LTS jammy openssh-client - 1:8.9p1-3ubuntu0.15 openssh-server - 1:8.9p1-3ubuntu0.15 --------------------------------------------------------------------------------- References o CVE-2026-35414 o CVE-2026-35388 o CVE-2026-35387 o CVE-2026-35386 o CVE-2026-35385 - --------------------------END INCLUDED TEXT---------------------- You have received this e-mail bulletin as a result of your organisation's registration with AUSCERT. 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