Vulnerability · Published Oct 13, 2021 · Assigned by AMD
CVE-2021-26318Side-channels Related to the x86 PREFETCH Instruction
Medium 4.7
In plain English
A medium-severity security flaw in All supported processors from AMD. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.3% (higher than 26% of all known vulnerabilities).
Severity (CVSS NVD)4.7Medium
Exploit odds (30 days)0.3%top 74.1% of all CVEs
Exploited in the wildNo reportsnot in CISA KEV
Attack toolingNoneno public tooling known
Official description
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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Ubuntu:22.04:LTS | amd64-microcode | no fix listed | UBUNTU-CVE-2021-26318 |
| Ubuntu:24.04:LTS | amd64-microcode | no fix listed | UBUNTU-CVE-2021-26318 |
| Ubuntu:25.10 | amd64-microcode | no fix listed | UBUNTU-CVE-2021-26318 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| AMD | All supported processors | unspecified – before undefined |
Weakness: CWE-208