CVE-2026-20716: Improper access control for some Intel(R) Processors within Ring 3: User Applications may allow an escalation
25
Routine
HIGH 7.0MITIGATEMITIGATEMITIGATE
CVE-2026-20716 is a high-severity flaw (CVSS 7.0) affecting xeon 634 firmware, xeon 636 firmware, xeon 638 firmware. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.
Improper access control for some Intel(R) Processors within Ring 3: User Applications may allow an escalation of privilege. Simple hardware adversary with an authenticated user combined with a high complexity attack may enable escalation of privilege. This result may potentially occur via local access when attack requirements are present with special internal knowledge and requires no user interaction. The potential vulnerability may impact the c
Why this priority
High severity
No fix is published yet: follow the downgrade or mitigation steps.
Last updated 2026-08-31 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score
Am I affected?
Timeline
Published CVE record published
Updated Record last modified
intel xeon 634 firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
intel xeon 636 firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
intel xeon 638 firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
intel xeon 654 firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
intel xeon 656 firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
intel xeon 658x firmware MITIGATE
Affected: all versions
Fixed in: no fixed release known
Safe to downgrade to: no unaffected older release
Check your OS release
cat /etc/os-release; uname -r
Debian / Ubuntu
sudo apt update && sudo apt full-upgrade
RHEL / Amazon Linux / Fedora
sudo dnf upgrade --refresh
Windows
Install the latest cumulative update from Windows Update
If no patch exists yet
OS downgrades are not safe. Apply the vendor mitigation from the advisory and restrict exposure.
Verify at the official sourceNVD · CVE Program · Report a problem with this page Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.
Quick answers
How do I fix CVE-2026-20716?
xeon 634 firmware: mitigate or apply the listed mitigation; xeon 636 firmware: mitigate or apply the listed mitigation; xeon 638 firmware: mitigate or apply the listed mitigation. Exact commands for each OS are on this page.
Is CVE-2026-20716 being exploited?
CVE-2026-20716 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.
What does CVE-2026-20716 affect?
CVE-2026-20716 affects xeon 634 firmware, xeon 636 firmware, xeon 638 firmware. Severity is high (CVSS 7.0). Improper access control for some Intel(R) Processors within Ring 3: User Applications may allow an escalation of privilege. Simple hardware adversary with an authenticated user combined with a high complexity attack may enable escalation of
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