========================================================================== Ubuntu Security Notice USN-8306-1 May 26, 2026
samba vulnerabilities ========================================================================== A security issue affects these releases of Ubuntu and its derivatives: - Ubuntu 26.04 LTS - Ubuntu 25.10 - Ubuntu 24.04 LTS - Ubuntu 22.04 LTS Summary: Several security issues were fixed in Samba. Software Description: - samba: SMB/CIFS file, print, and login server for Unix Details: Asim Viladi Oglu Manizada discovered that Samba incorrectly handled access checks on reparse point operations. An attacker could possibly use this issue to modify reparse point extended attributes on files that should have been read-only. This issue only affected Ubuntu 25.10 and Ubuntu 26.04 LTS. (CVE-2026-1933) Pavel Kohout discovered that Samba's vfs_worm module did not properly block file overwrites. An attacker could possibly use this issue to overwrite files that should have remained immutable. (CVE-2026-2340) Arad Inbar, Nir Somech, and Ben Grinberg discovered that Samba incorrectly handled certificate auto-enrolment group policies over HTTP without verification. A machine-in-the-middle attacker could possibly use this issue to install a malicious CA certificate. This issue only affected Ubuntu 24.04 LTS, Ubuntu 25.10, and Ubuntu 26.04 LTS. (CVE-2026-3012) Arad Inbar, Erez Cohen, Nir Somech, and Ben Grinberg discovered that Samba's Active Directory Domain Controller WINS server could be made to crash under certain circumstances. A remote attacker could possibly use this issue to cause a denial of service. (CVE-2026-3238) Ron Ben Yizhak discovered that Samba's DCE/RPC SAMR server incorrectly handled a non-default password check script configuration. A remote attacker could possibly use this issue to execute arbitrary code. (CVE-2026-4408) Ron Ben Yizhak discovered that Samba's printing subsystem incorrectly handled a non-default print command configuration. A remote attacker could possibly use this issue to execute arbitrary code. (CVE-2026-4480) Update instructions: The problem can be corrected by updating your system to the following package versions: Ubuntu 26.04 LTS samba 2:4.23.6+dfsg-1ubuntu2.1 Ubuntu 25.10 samba 2:4.22.3+dfsg-4ubuntu2.4 Ubuntu 24.04 LTS samba 2:4.19.5+dfsg-4ubuntu9.6 Ubuntu 22.04 LTS samba 2:4.15.13+dfsg-0ubuntu1.12 In general, a standard system update will make all the necessary changes. References: https://ubuntu.com/security/notices/USN-8306-1 CVE-2026-1933, CVE-2026-2340, CVE-2026-3012, CVE-2026-3238, CVE-2026-4408, CVE-2026-4480 Package Information: https://launchpad.net/ubuntu/+source/samba/2:4.23.6+dfsg-1ubuntu2.1 https://launchpad.net/ubuntu/+source/samba/2:4.22.3+dfsg-4ubuntu2.4 https://launchpad.net/ubuntu/+source/samba/2:4.19.5+dfsg-4ubuntu9.6 https://launchpad.net/ubuntu/+source/samba/2:4.15.13+dfsg-0ubuntu1.12
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