Summary
Error on unsupported architectures in raw-cpuid
native_cpuid::cpuid_count() exposes the unsafe __cpuid_count() intrinsic from core::arch::x86 or core::arch::x86_64 as a safe function, and uses it internally, without checking the safety requirement:
- The CPU the program is currently running on supports the function being called.
CPUID is available in most, but not all, x86/x86_64 environments. The crate compiles only on these architectures, so others are unaffected. This issue is mitigated by the fact that affected programs are expected to crash deterministically every time.
The flaw has been fixed in v9.0.0, by intentionally breaking compilation when targeting SGX or 32-bit x86 without SSE. This covers all affected CPUs.
Impact
Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service. Typical impact: denial of service.
CVE-2021-26307 has a CVSS score of 5.5 (Medium). The vector is requires local access, low privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (9.0.0); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
Already deployed Kodem?
See it in your environmentNew to Kodem? Get a demo →Remediation advice
Kodem Kai can prioritize this vulnerability in your dependency tree and generate a fix recommendation.
Frequently Asked Questions
- What is CVE-2021-26307? CVE-2021-26307 is a medium-severity uncontrolled resource consumption vulnerability in raw-cpuid (rust), affecting versions < 9.0.0. It is fixed in 9.0.0. Crafted input forces the application to consume excessive CPU, memory, or other resources, degrading or denying service.
- How severe is CVE-2021-26307? CVE-2021-26307 has a CVSS score of 5.5 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of raw-cpuid are affected by CVE-2021-26307? raw-cpuid (rust) versions < 9.0.0 is affected.
- Is there a fix for CVE-2021-26307? Yes. CVE-2021-26307 is fixed in 9.0.0. Upgrade to this version or later.
- Is CVE-2021-26307 exploitable, and should I be worried? Whether CVE-2021-26307 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2021-26307 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2021-26307? Upgrade
raw-cpuidto 9.0.0 or later.