How severe is CVE-2021-32810?

CVE-2021-32810 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2021-32810?

CVE-2021-32810 affects the following packages: crossbeam-deque (crates.io), crossbeam-deque (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2021-32810?

Update crossbeam-deque to 0.7.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-32810 is resolved across your whole dependency graph.

How do I detect CVE-2021-32810 in my crates.io dependencies?

Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crossbeam-deque, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

How do I mitigate CVE-2021-32810 if there is no patch (or I can't update yet)?

Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Is CVE-2021-32810 actively exploited in the wild?

No public exploit code has been indexed for CVE-2021-32810 yet. This does not mean the vulnerability cannot be exploited — absence of public exploits does not imply safety. Apply the recommended fix and use O3 Security to monitor your exposure.

What is the EPSS score for CVE-2021-32810?

CVE-2021-32810 has an EPSS (Exploit Prediction Scoring System) score of 1.9%, placing it in the 79th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

What type of vulnerability is CVE-2021-32810?

CVE-2021-32810 is classified as CWE-362 (CWE-362). This weakness type describe the underlying flaw category, which helps determine the potential impact and the right class of mitigation.

When was CVE-2021-32810 published, and has it been updated?

CVE-2021-32810 was published on August 2, 2021 and was last updated on July 8, 2026. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀

🦀 crates.io

Not in CISA KEV

CRITICAL severity

CVE-2021-32810 — crossbeam-deque

CRITICAL

CVE-2021-32810 is a critical-severity (CVSS 9.8) CWE-362 vulnerability in crossbeam-deque. A fix is available for crossbeam-deque — see the affected versions and patch details below.

crossbeam-deque Data Race before v0.7.4 and v0.8.1

Also known asGHSA-pqqp-xmhj-wgcwRUSTSEC-2021-0093

Published

Aug 2, 2021

Updated

Jul 8, 2026

Affected

2 pkgs

Patched

2 / 2

Exploits

None indexed

Exploitation data as of Oct 10, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.9%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs79th percentile — riskier than 79% of all scored CVEsHighest risk

Probability of exploitation in the next 30 days, from FIRST.org EPSS.

How urgent is this, really

CVE-2021-32810 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,386 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.

Real-World Exposure

2 pkgs affected

🦀crossbeam-deque🦀crossbeam-deque

Real-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

Impact

In the affected version of this crate, the result of the race condition is that one or more tasks in the worker queue can be popped twice instead of other tasks that are forgotten and never popped. If tasks are allocated on the heap, this can cause double free and a memory leak. If not, this still can cause a logical bug.

Crates using Stealer::steal, Stealer::steal_batch, or Stealer::steal_batch_and_pop are affected by this issue.

Patches

This has been fixed in crossbeam-deque 0.8.1 and 0.7.4.

Credits

This issue was reported and fixed by Maor Kleinberger.

License

This advisory is in the public domain.

Affected Packages

2 total 2 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`crossbeam-deque`	all versions	0.7.4`cargo update -p crossbeam-deque --precise 0.7.4`
🦀crates.io	`crossbeam-deque`	≥ 0.8.0&&< 0.8.1	0.8.1`cargo update -p crossbeam-deque --precise 0.8.1`

Affected Products

2 products · 3 configurations

Application

crossbeamcrossbeam_project

≥ 0.8.0 && < 0.8.1

range

fedorafedoraproject

1 version

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for crossbeam-deque, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update crossbeam-deque to 0.7.4 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-32810 is resolved across your whole dependency graph.
Workarounds
Constrain what reaches the vulnerable code: limit the size and shape of untrusted input, isolate the affected component in a sandboxed or least-privileged process, and enable the platform's memory-safety mitigations (ASLR, stack protector, hardened allocator) so an out-of-bounds access is more likely to fail closed than to be exploitable.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatModerate

Product	Fixed in	Advisory
Red Hat Enterprise Linux 7	`firefox-0:91.2.0-4.el7_9`	RHSA-2021:3791
Red Hat Enterprise Linux 7	`thunderbird-0:91.2.0-1.el7_9`	RHSA-2021:3841
Red Hat Enterprise Linux 8	`firefox-0:91.2.0-4.el8_4`	RHSA-2021:3755
Red Hat Enterprise Linux 8	`thunderbird-0:91.2.0-1.el8_4`	RHSA-2021:3838
Red Hat Enterprise Linux 8.1 Extended Update Support	`firefox-0:91.2.0-4.el8_1`	RHSA-2021:3757
Red Hat Enterprise Linux 8.1 Extended Update Support	`thunderbird-0:91.2.0-1.el8_1`	RHSA-2021:3840
Red Hat Enterprise Linux 8.2 Extended Update Support	`firefox-0:91.2.0-4.el8_2`	RHSA-2021:3756
Red Hat Enterprise Linux 8.2 Extended Update Support	`thunderbird-0:91.2.0-1.el8_2`	RHSA-2021:3839

UbuntuCRITICAL

USN-5107-1Ubuntu USN-5132-1Ubuntu

Frequently Asked Questions

### Impact In the affected version of this crate, the result of the race condition is that one or more tasks in the worker queue can be popped twice instead of other tasks that are forgotten and never popped. If tasks are allocated on the heap, this can cause double free and a memory leak. If not, this still can cause a logical bug. Crates using `Stealer::steal`, `Stealer::steal_batch`, or `Stealer::steal_batch_and_pop` are affected by this issue. ### Patches This has been fixed in crossbeam-deque 0.8.1 and 0.7.4. ### Credits This issue was reported and fixed by Maor Kleinberger. ### Li

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