What is CVE-2022-23639?

CVE-2022-23639 is a high-severity race condition vulnerability in crossbeam-utils (rust), affecting versions < 0.8.7. It is fixed in 0.8.7. Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing.

How severe is CVE-2022-23639?

CVE-2022-23639 has a CVSS score of 8.1 (High). 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 crossbeam-utils are affected by CVE-2022-23639?

crossbeam-utils (rust) versions < 0.8.7 is affected.

Is there a fix for CVE-2022-23639?

Yes. CVE-2022-23639 is fixed in 0.8.7. Upgrade to this version or later.

Is CVE-2022-23639 exploitable, and should I be worried?

Whether CVE-2022-23639 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.

What actually determines whether CVE-2022-23639 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-2022-23639?

Upgrade crossbeam-utils to 0.8.7 or later.

CVE-2022-23639 in crossbeam-utils

Q: How severe is CVE-2022-23639?

CVE-2022-23639 has a CVSS score of 8.1 (High). 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.

Q: Which versions of crossbeam-utils are affected by CVE-2022-23639?

crossbeam-utils (rust) versions < 0.8.7 is affected.

Q: Is there a fix for CVE-2022-23639?

Yes. CVE-2022-23639 is fixed in 0.8.7. Upgrade to this version or later.

Q: Is CVE-2022-23639 exploitable, and should I be worried?

Whether CVE-2022-23639 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.

Q: What actually determines whether CVE-2022-23639 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.

Q: How do I fix CVE-2022-23639?

Upgrade crossbeam-utils to 0.8.7 or later.

Summary

crossbeam-utils Unsoundness of AtomicCell<{i,u}64> arithmetics on 32-bit targets that support Atomic{I,U}64

References

https://github.com/crossbeam-rs/crossbeam/pull/781

License

This advisory is in the public domain.

Impact

The affected versions of this crate incorrectly assumed that the alignment of {i,u}64 was always the same as Atomic{I,U}64.

However, the alignment of {i,u}64 on a 32-bit target can be smaller than Atomic{I,U}64.

This can cause the following problems:

Unaligned memory accesses
Data race

Crates using fetch_* methods with AtomicCell<{i,u}64> are affected by this issue.

32-bit targets without Atomic{I,U}64 and 64-bit targets are not affected by this issue.
32-bit targets with Atomic{I,U}64 and {i,u}64 have the same alignment are also not affected by this issue.

The following is a complete list of the builtin targets that may be affected. (last update: nightly-2022-02-11)

armv7-apple-ios (tier 3)
armv7s-apple-ios (tier 3)
i386-apple-ios (tier 3)
i586-unknown-linux-gnu
i586-unknown-linux-musl
i686-apple-darwin (tier 3)
i686-linux-android
i686-unknown-freebsd
i686-unknown-haiku (tier 3)
i686-unknown-linux-gnu
i686-unknown-linux-musl
i686-unknown-netbsd (tier 3)
i686-unknown-openbsd (tier 3)
i686-wrs-vxworks (tier 3)

(script to get list)

Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing. Typical impact: TOCTOU exploits, data corruption, or privilege escalation.

CVE-2022-23639 has a CVSS score of 8.1 (High). The vector is network-reachable, no 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 (0.8.7); upgrading removes the vulnerable code path.

Affected versions

crossbeam-utils (< 0.8.7)

Security releases

crossbeam-utils → 0.8.7 (rust)

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 environment New to Kodem? Get a demo →

Remediation advice

This has been fixed in crossbeam-utils 0.8.7.

Affected 0.8.x releases have been yanked.

Frequently Asked Questions

What is CVE-2022-23639? CVE-2022-23639 is a high-severity race condition vulnerability in crossbeam-utils (rust), affecting versions < 0.8.7. It is fixed in 0.8.7. Multiple concurrent operations access a shared resource without proper synchronization, producing unpredictable results depending on timing.
How severe is CVE-2022-23639? CVE-2022-23639 has a CVSS score of 8.1 (High). 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 crossbeam-utils are affected by CVE-2022-23639? crossbeam-utils (rust) versions < 0.8.7 is affected.
Is there a fix for CVE-2022-23639? Yes. CVE-2022-23639 is fixed in 0.8.7. Upgrade to this version or later.
Is CVE-2022-23639 exploitable, and should I be worried? Whether CVE-2022-23639 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-2022-23639 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-2022-23639? Upgrade crossbeam-utils to 0.8.7 or later.