How severe is CVE-2021-26306?

CVE-2021-26306 has a CVSS score of 7.5/10, rated HIGH. Immediate patching is strongly recommended.

Which products are affected by CVE-2021-26306?

CVE-2021-26306 affects the following products: raw-cpuid_project raw-cpuid.

How do I patch CVE-2021-26306?

Apply the raw-cpuid_project raw-cpuid security patch or hotfix for CVE-2021-26306 on the affected version, following the vendor advisory for your exact build.

How do I detect CVE-2021-26306 across my infrastructure?

Inventory every raw-cpuid_project raw-cpuid deployment and check each version against the affected-products list above.

How do I mitigate CVE-2021-26306 if there is no patch (or I can't update yet)?

If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Is CVE-2021-26306 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-26306 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-26306?

CVE-2021-26306 has an EPSS (Exploit Prediction Scoring System) score of 1.3%, placing it in the 69th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

Which products and versions are affected by CVE-2021-26306?

CVE-2021-26306 affects raw-cpuid_project raw-cpuid. Check the affected-products list on this page against your deployed version to confirm exposure.

When was CVE-2021-26306 published, and has it been updated?

CVE-2021-26306 was published on January 29, 2021 and was last updated on June 17, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🛡️

Not in CISA KEV

HIGH severity

CVE-2021-26306 — Raw-Cpuid

HIGH

CVE-2021-26306 is a high-severity (CVSS 7.5) vulnerability in raw-cpuid_project raw-cpuid. A fix is available — see the affected versions and patch details below.

An issue was discovered in the raw-cpuid crate before 9.0.0 for Rust. It has unsound transmute calls within as_string() methods.

Published

Jan 29, 2021

Updated

Jun 17, 2026

Affected

1 product

Patched

See advisory

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.3%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs69th percentile — riskier than 69% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-26306 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Description

An issue was discovered in the raw-cpuid crate before 9.0.0 for Rust. It has unsound transmute calls within as_string() methods.

Affected Products

1 product · 1 configurations

Application

raw-cpuidraw-cpuid_project

< 9.0.0

range

Detection & mitigation playbook

Vendor / appliance

Detect
Inventory every raw-cpuid_project raw-cpuid deployment and check each version against the affected-products list above.
Fix
Apply the raw-cpuid_project raw-cpuid security patch or hotfix for CVE-2021-26306 on the affected version, following the vendor advisory for your exact build.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands. Alongside that, restrict the management interface to trusted networks and apply the vendor's recommended configuration mitigations.

Frequently Asked Questions

An issue was discovered in the raw-cpuid crate before 9.0.0 for Rust. It has unsound transmute calls within as_string() methods.

O3 Security · Runtime Protection

Is CVE-2021-26306 being exploited in your environment?

Detect and block the exploit chain at execution, on systems you cannot patch yet.

Protect my workloads How runtime protection works

CVE-2021-26306 — Raw-Cpuid

EPSS Exploitation Probability

How urgent is this, really

Where this sits among everything scored

Description

Affected Products

Detection & mitigation playbook

Detect

Fix

Workarounds

Frequently Asked Questions

Is CVE-2021-26306 being exploited in your environment?