{"id":"CVE-2021-46778","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-46778","generatedAt":"2026-10-27T21:48:23.402Z","title":"Execution unit scheduler contention may lead to a side channel vulnerability found on AMD CPU microarchitectures codenamed “Zen 1”, “Zen 2” and “Zen 3” that use simultaneous multithreading (SMT).","description":"Execution unit scheduler contention may lead to a side channel vulnerability found on AMD CPU microarchitectures codenamed “Zen 1”, “Zen 2” and “Zen 3” that use simultaneous multithreading (SMT). By measuring the contention level on scheduler queues an attacker may potentially leak sensitive information.","published":"2022-08-10T20:15:25.000Z","lastModified":"2026-06-17T04:15:33.000Z","status":"Modified","sourceIdentifier":"psirt@amd.com","cvss":{"version":"3.1","score":5.6,"severity":"MEDIUM","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:C/C:H/I:N/A:N"},"cwe":["CWE-203"],"affected":["amd/athlon 3050ge firmware","amd/athlon 3150g firmware","amd/athlon 3150ge firmware","amd/epyc 7001 firmware","amd/epyc 7002 firmware","amd/epyc 7003 firmware","amd/epyc 7232p firmware","amd/epyc 7251 firmware","amd/epyc 7252 firmware","amd/epyc 7261 firmware","amd/epyc 7262 firmware","amd/epyc 7272 firmware","amd/epyc 7281 firmware","amd/epyc 7282 firmware","amd/epyc 72f3 firmware","amd/epyc 7301 firmware","amd/epyc 7302 firmware","amd/epyc 7302p firmware","amd/epyc 7313 firmware","amd/epyc 7313p firmware","amd/epyc 7343 firmware","amd/epyc 7351 firmware","amd/epyc 7351p firmware","amd/epyc 7352 firmware","amd/epyc 7371 firmware","amd/epyc 7373x firmware","amd/epyc 73f3 firmware","amd/epyc 7401 firmware","amd/epyc 7401p firmware","amd/epyc 7402 firmware","amd/epyc 7402p firmware","amd/epyc 7413 firmware","amd/epyc 7443 firmware","amd/epyc 7443p firmware","amd/epyc 7451 firmware","amd/epyc 7452 firmware","amd/epyc 7453 firmware","amd/epyc 7473x firmware","amd/epyc 74f3 firmware","amd/epyc 7501 firmware","amd/epyc 7502 firmware","amd/epyc 7502p firmware","amd/epyc 7513 firmware","amd/epyc 7532 firmware","amd/epyc 7542 firmware","amd/epyc 7543 firmware","amd/epyc 7543p firmware","amd/epyc 7551 firmware","amd/epyc 7551p firmware","amd/epyc 7552 firmware","amd/epyc 7573x firmware","amd/epyc 75f3 firmware","amd/epyc 7601 firmware","amd/epyc 7642 firmware","amd/epyc 7643 firmware","amd/epyc 7662 firmware","amd/epyc 7663 firmware","amd/epyc 7702 firmware","amd/epyc 7702p firmware","amd/epyc 7713 firmware"],"epss":{"score":0.00239,"percentile":0.14804,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.24%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1039","tags":["Vendor Advisory"],"source":"psirt@amd.com"},{"url":"https://www.amd.com/en/corporate/product-security/bulletin/amd-sb-1039","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-46778","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}