CVE-2021-26307: An issue was discovered in the raw-cpuid crate before 9.0.0 for Rust

Q: How do I fix CVE-2021-26307?

raw-cpuid: upgrade to 9.0.0. Exact commands for each OS are on this page.

Q: Is CVE-2021-26307 being exploited?

CVE-2021-26307 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2021-26307 affect?

CVE-2021-26307 affects raw-cpuid. Severity is medium (CVSS 5.5). An issue was discovered in the raw-cpuid crate before 9.0.0 for Rust. It allows __cpuid_count() calls even if the processor does not support the CPUID instruction, which is unsound and causes a deterministic crash.

Q: How urgent is CVE-2021-26307?

Priority 31/100. Public exploit reference

Routine

MEDIUM 5.5UPGRADE

CVE-2021-26307 is a medium-severity flaw (CVSS 5.5) affecting raw-cpuid. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

An issue was discovered in the raw-cpuid crate before 9.0.0 for Rust. It allows __cpuid_count() calls even if the processor does not support the CPUID instruction, which is unsound and causes a deterministic crash.

Why this priority

Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	5.5 (Medium)
Attack vector	Local
Attack complexity	Low
Privileges needed	Low
User interaction	None
EPSS exploit chance	0.3% (top 72%)
CISA exploited list	No
Published	2021-01-29
Last modified	2026-06-17

Publisher (CNA): MITRE · Vendor: raw-cpuid project

Last updated 2026-06-17 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2021-01-29 03:15 UTCPublished CVE record published
2026-06-17 03:43 UTCUpdated Record last modified

raw-cpuid project raw-cpuid UPGRADE

Affected: < 9.0.0

Fixed in: 9.0.0

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy raw-cpuid || rpm -q raw-cpuid || raw-cpuid --version

2. UPGRADE to 9.0.0 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade raw-cpuid

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade raw-cpuid

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · 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-2021-26307?

raw-cpuid: upgrade to 9.0.0. Exact commands for each OS are on this page.

Is CVE-2021-26307 being exploited?

CVE-2021-26307 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-2021-26307 affect?

CVE-2021-26307 affects raw-cpuid. Severity is medium (CVSS 5.5). An issue was discovered in the raw-cpuid crate before 9.0.0 for Rust. It allows __cpuid_count() calls even if the processor does not support the CPUID instruction, which is unsound and causes a deterministic crash.

How urgent is CVE-2021-26307?

Priority 31/100. Public exploit reference

Related CVEs

CVE-2021-45687 CRITICAL 9.8 UPGRADE An issue was discovered in the raw-cpuid crate before 9.1.1 for Rust
CVE-2021-26306 HIGH 7.5 UPGRADE An issue was discovered in the raw-cpuid crate before 9.0.0 for Rust

References

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