Ubuntu Security Notices USN-8430-1 USN-8430-1: ADSys vulnerabilities Publication date 15 June 2026 Overview Several security issues were fixed in ADSys. Releases 26.04 LTS 25.10 24.04 LTS 22.04 LTS 20.04 LTS Open side navigation Close side navigation Packages Details Update instructions References Packages adsys - Active Directory Group Policy client Details It was discovered that ADSys did not properly handle certain HTTP/2 frames. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 26.04 LTS. ( CVE-2026-27141 ) It was discovered that ADSys did not properly handle certain HTTP/2 SETTINGS frames. A remote attacker could possibly use this issue to cause a denial of service. ( CVE-2026-33814 ) It was discovered that ADSys did not properly handle certain HTTP/2 frames. A remote attacker could possibly use this issue to cause a denial of service. This issue only affected Ubuntu 26.04 LTS. ( CVE-2026-27141 ) It was discovered that ADSys did not properly handle certain HTTP/2 SETTINGS frames. A remote attacker could possibly use this issue to cause a denial of service. ( CVE-2026-33814 ) 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 adsys – 0.16.4ubuntu1.1 25.10 questing adsys – 0.16.3ubuntu0.25.10.2 24.04 LTS noble adsys – 0.16.3~24.04.2ubuntu0.24.04.1 22.04 LTS jammy adsys – 0.16.3~22.04.2ubuntu0.22.04.1 20.04 LTS focal adsys – 0.9.2~20.04.2ubuntu0.1+esm2 Ubuntu Pro Fix available with Ubuntu Pro . 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. Get Ubuntu Pro References CVE-2026-33814 CVE-2026-27141 CVE-2026-33814 CVE-2026-27141