{"id":"UBUNTU-CVE-2021-26318","details":"A timing and power-based side channel attack leveraging the x86 PREFETCH instructions on some AMD CPUs could potentially result in leaked kernel address space information.","modified":"2026-01-27T12:20:42.568586Z","published":"2021-10-13T19:15:00Z","withdrawn":"2026-01-27T10:41:33Z","upstream":["CVE-2021-26318"],"references":[{"type":"REPORT","url":"https://ubuntu.com/security/CVE-2021-26318"},{"type":"REPORT","url":"https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1017"},{"type":"REPORT","url":"https://www.cve.org/CVERecord?id=CVE-2021-26318"}],"affected":[{"package":{"name":"amd64-microcode","ecosystem":"Ubuntu:14.04:LTS","purl":"pkg:deb/ubuntu/amd64-microcode@3.20180524.1~ubuntu0.14.04.2+really20130710.1ubuntu1?arch=source&distro=trusty"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["1.20120910-3","2.20131007.1+really20130710.1","3.20180524.1~ubuntu0.14.04.1","3.20180524.1~ubuntu0.14.04.2+really20130710.1","3.20180524.1~ubuntu0.14.04.2+really20130710.1ubuntu1"],"ecosystem_specific":{"binaries":[{"binary_name":"amd64-microcode","binary_version":"3.20180524.1~ubuntu0.14.04.2+really20130710.1ubuntu1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26318.json"}},{"package":{"name":"amd64-microcode","ecosystem":"Ubuntu:Pro:16.04:LTS","purl":"pkg:deb/ubuntu/amd64-microcode@3.20191021.1+really3.20180524.1~ubuntu0.16.04.2+esm3?arch=source&distro=esm-infra/xenial"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["2.20141028.1","2.20160316.1","3.20180524.1~ubuntu0.16.04.1","3.20180524.1~ubuntu0.16.04.2","3.20191021.1ubuntu0.16.04.1","3.20191021.1+really3.20180524.1~ubuntu0.16.04.2","3.20191021.1+really3.20180524.1~ubuntu0.16.04.2+esm1","3.20191021.1+really3.20180524.1~ubuntu0.16.04.2+esm2","3.20191021.1+really3.20180524.1~ubuntu0.16.04.2+esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"amd64-microcode","binary_version":"3.20191021.1+really3.20180524.1~ubuntu0.16.04.2+esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26318.json"}},{"package":{"name":"amd64-microcode","ecosystem":"Ubuntu:Pro:18.04:LTS","purl":"pkg:deb/ubuntu/amd64-microcode@3.20191021.1+really3.20181128.1~ubuntu0.18.04.1+esm3?arch=source&distro=esm-infra/bionic"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.20160316.3","3.20171205.1","3.20180524.1~ubuntu0.18.04.1","3.20180524.1~ubuntu0.18.04.2","3.20191021.1ubuntu0.18.04.2","3.20191021.1+really3.20181128.1~ubuntu0.18.04.1","3.20191021.1+really3.20181128.1~ubuntu0.18.04.1+esm1","3.20191021.1+really3.20181128.1~ubuntu0.18.04.1+esm2","3.20191021.1+really3.20181128.1~ubuntu0.18.04.1+esm3"],"ecosystem_specific":{"binaries":[{"binary_name":"amd64-microcode","binary_version":"3.20191021.1+really3.20181128.1~ubuntu0.18.04.1+esm3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26318.json"}},{"package":{"name":"amd64-microcode","ecosystem":"Ubuntu:20.04:LTS","purl":"pkg:deb/ubuntu/amd64-microcode@3.20191218.1ubuntu1.3?arch=source&distro=focal"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.20181128.1ubuntu2","3.20191021.1ubuntu1","3.20191218.1ubuntu1","3.20191218.1ubuntu1.1","3.20191218.1ubuntu1.2","3.20191218.1ubuntu1.3"],"ecosystem_specific":{"binaries":[{"binary_name":"amd64-microcode","binary_version":"3.20191218.1ubuntu1.3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26318.json"}},{"package":{"name":"amd64-microcode","ecosystem":"Ubuntu:22.04:LTS","purl":"pkg:deb/ubuntu/amd64-microcode@3.20191218.1ubuntu2.3?arch=source&distro=jammy"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.20191218.1ubuntu2","3.20191218.1ubuntu2.1","3.20191218.1ubuntu2.2","3.20191218.1ubuntu2.3"],"ecosystem_specific":{"binaries":[{"binary_name":"amd64-microcode","binary_version":"3.20191218.1ubuntu2.3"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26318.json"}},{"package":{"name":"amd64-microcode","ecosystem":"Ubuntu:24.04:LTS","purl":"pkg:deb/ubuntu/amd64-microcode@3.20250311.1ubuntu0.24.04.1?arch=source&distro=noble"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.20230808.1.1ubuntu1","3.20231019.1ubuntu1","3.20231019.1ubuntu2","3.20231019.1ubuntu2.1","3.20250311.1ubuntu0.24.04.1"],"ecosystem_specific":{"binaries":[{"binary_name":"amd64-microcode","binary_version":"3.20250311.1ubuntu0.24.04.1"}]},"database_specific":{"source":"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2021/UBUNTU-CVE-2021-26318.json"}},{"package":{"name":"amd64-microcode","ecosystem":"Ubuntu:25.10","purl":"pkg:deb/ubuntu/amd64-microcode@3.20250708.1ubuntu1?arch=source&distro=questing"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"}]}],"versions":["3.20240820.1ubuntu1","3.20250311.1ubun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