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

Exploitation

No confirmed exploitation recorded. Patch Next marks exploitation only from CISA KEV.

CVSS

8.1 · CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS

• CVE-2022-23639: 1.23% estimated exploitation activity in the next 30 days; percentile 68.94 (FIRST EPSS, 2026-11-03). This is a model estimate, not proof of exploitation or customer exposure.

As published by the source; long descriptions are shortened.

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…

Published by the source

16 Feb 2022, 22:36 UTC

Last modified by the source

4 Feb 2025, 17:30 UTC

Source last checked

26 Oct 2026, 15:38 UTC

1. Revision 1 · created · 26 Oct 2026

   Published from ghsa record GHSA-qc84-gqf4-9926

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# Patch Next advisory brief: CVE-2022-23639

Advisory: crossbeam-utils Unsoundness of AtomicCell arithmetics on 32-bit targets that support Atomic{I,U}64
IDs: CVE-2022-23639, GHSA-qc84-gqf4-9926
Record: https://patchnext.com/advisories/cve-2022-23639 (revision 1, source checked 26 Oct 2026, 15:38 UTC)
Inventory: none attached. This brief comes from a public page and does not say whether any deployment is affected.
Severity: High (CVSS 8.1)
Exploitation: no confirmed exploitation recorded. Patch Next confirms exploitation only from CISA KEV.
Vendor response: Vendor fix available; fixed versions by package: crossbeam-utils 0.8.7. A vendor fix does not mean a deployment is fixed.

## Affected components
- crates.io crossbeam-utils: affected < 0.8.7; fixed in 0.8.7

## Suggested inspection (read-only)
- crates.io crossbeam-utils: check the installed version with your package manager.

## Supported action
Upgrade each affected component to a fixed version on its release line. For a transitive dependency, upgrade the parent package or add an override or constraint, then regenerate the lockfile. Redeploy every environment that ran an affected version.

## Required regression checks
- Run the test suite and a production build.
- Exercise the features that depend on crossbeam-utils.
- Repeat the inspection and confirm that only fixed versions remain installed.

## Rollback considerations
- Keep the previous lockfile and deployment artifact. Rolling back reinstates the vulnerable version, so apply any documented mitigation while you fix forward.

## Unresolved questions
- Which deployments run an affected version?
- Exploitation status can change. Check again before lowering the priority.
- Mark the work resolved only after the fixed version is verified in production.

## Sources
- Verified: https://github.com/advisories/GHSA-qc84-gqf4-9926 (GitHub-reviewed advisory GHSA-qc84-gqf4-9926 lists affected ranges: crates.io crossbeam-utils >=0 <0.8.7)

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