CVE-2021-26307

Deterministic crash via unchecked CPUID call

Published Jan 29, 2021 · Updated Aug 3, 2024

Denial-of-service in Rust raw-cpuid before 9.0.0 allows local users to trigger deterministic crashes via unsupported CPUID calls. The native_cpuid::cpuid_count() function exposes the unsafe __cpuid_count() intrinsic as a safe function without checking whether the processor supports the requested instruction. The affected program must run on an x86 or x86_64 CPU lacking that CPUID support, and the consequence is a repeatable service crash without confidentiality or integrity impact.

CVSS severity5.5
Medium
EPSS probability0.34%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Denial-of-service in Rust raw-cpuid before 9.0.0 allows local users to trigger deterministic crashes via unsupported CPUID calls. The native_cpuid::cpuid_count() function exposes the unsafe __cpuid_count() intrinsic as a safe function without checking whether the processor supports the requested instruction. The affected program must run on an x86 or x86_64 CPU lacking that CPUID support, and the consequence is a repeatable service crash without confidentiality or integrity impact.

The record

CVE
CVE-2021-26307
Published
Jan 29, 2021
Updated
Aug 3, 2024
Vendor
Unknown vendor
Product
Unknown product
Classifications
CWE-657, CWE-400, T1499
Attack vector
local
Privileges
authenticated

Timeline

How it unfolded

  1. Jan 29, 2021CVE publishedPublication date reported by the CVE source.
  2. Aug 3, 2024Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Affected buildAffected product and version details are unavailable.

What conditions does exploitation require?

Attack vectorlocal
Required privilegesauthenticated

What is affected?

Affected products and versions are unavailable in this record.

Published CVSS scores

2.1NVDAV:L/AC:L/Au:N/C:N/I:N/A:P
5.5NVDCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectorlocal
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

CWE-657Violation of Secure Design Principles
CWE-400Uncontrolled Resource Consumption
T1499Endpoint Denial of Service

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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