CVE-2022-23639 is a high-severity (CVSS 8.1) CWE-362 vulnerability in crossbeam-utils. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2022-23639 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Restriction of Operations within the Bounds of a Memory Buffer and Race Condition in crossbeam-utils
Real-World Exposure
crossbeam-utilsReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects crates.io packages — download data is not available via public APIs for these ecosystems.
Description
crossbeam-utils provides atomics, synchronization primitives, scoped threads, and other utilities for concurrent programming in Rust. crossbeam-utils prior to version 0.8.7 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 unaligned memory accesses and 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. This has been fixed in crossbeam-utils 0.8.7. There are currently no known workarounds.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | crossbeam-utils | all versions | 0.8.7 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crossbeam-utils. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update crossbeam-utils to 0.8.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2022-23639 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 pinpoints whether CVE-2022-23639 is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to CVE-2022-23639. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2022-23639 in your dependencies?
O3 detects CVE-2022-23639 across crates.io dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.