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CVE-2021-32810· NVD / CVE Program· CNA GitHub_M

Data race in crossbeam-deque

crossbeam-deque is a package of work-stealing deques for building task schedulers when programming in Rust. In versions prior to 0.7.4 and 0.8.0, 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. This has been fixed in crossbeam-deque 0.8.1 and 0.7.4.

CriticalCVSS 9.8 · v3.1—No exploit Fix available
Published
Aug 2, 2021
Updated
Jun 16, 2026
EPSS
1.9% · 79th percentile
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Report tools

JSON

Action score

40

Plan

Add it to your regular patch cycle.

CVSS
39 / 40 · 9.8 / 10
CISA KEV
0 / 30 · Not listed
EPSS
1 / 30 · 1.9%

CNA vs NVD score

NVD
9.8
CNA · GitHub_M
9.8
agree

The score given by the assigning authority versus NVD’s independent score. A gap means the severity is contested.

Affected systems

VendorProduct
crossbeam projectcrossbeam
fedoraprojectfedora

Affected versions

NVD version ranges (for catalog products). Add the product to your stack with a version and matching uses these.

  • crossbeam project crossbeambefore 0.7.4
  • crossbeam project crossbeam0.8.0 and later · before 0.8.1
  • fedoraproject fedora34

Versions reported by the vendor

Affected version ranges reported by the assigning authority (GitHub_M). Independent of NVD's CPE analysis and usually ahead of it.

  • crossbeam-rs crossbeam

    • < 0.7.4, >= 0.8.0, < 0.8.1affected

Package-level exposure

OSV and GitHub Advisory data: ecosystem, package and range. SBOM matching uses this table.

EcosystemPackageAffected rangeFix
crates.iocrossbeam-dequefrom 0.0.0-0 · before 0.7.40.7.4
crates.iocrossbeam-dequefrom 0.8.0 · before 0.8.10.8.1
crates.iocrossbeam-dequefrom 0.8.0 · before 0.8.10.8.1
crates.iocrossbeam-dequebefore 0.7.40.7.4
Debian:12rust-crossbeam-dequebefore 0.7.4-10.7.4-1
openSUSE:Leap 15.2MozillaFirefoxbefore 91.2.0-lp152.2.67.191.2.0-lp152.2.67.1
openSUSE:Leap 15.2MozillaThunderbirdbefore 91.4.0-lp152.2.52.191.4.0-lp152.2.52.1
openSUSE:Leap 15.2rust-cbindgenbefore 0.19.0-lp152.2.7.10.19.0-lp152.2.7.1
openSUSE:Leap 15.3MozillaFirefoxbefore 91.2.0-8.54.191.2.0-8.54.1
openSUSE:Leap 15.3MozillaFirefox-branding-SLEbefore 91-9.5.191-9.5.1
openSUSE:Leap 15.3MozillaThunderbirdbefore 91.4.0-8.45.291.4.0-8.45.2
openSUSE:Leap 15.3rust-cbindgenbefore 0.19.0-1.9.10.19.0-1.9.1
openSUSE:TumbleweedMozillaFirefoxbefore 93.0-1.193.0-1.1
openSUSE:TumbleweedMozillaThunderbirdbefore 91.2.0-1.191.2.0-1.1
Red Hat:enterprise_linux:7::clientfirefoxbefore 0:91.2.0-4.el7_90:91.2.0-4.el7_9
Red Hat:enterprise_linux:7::clientfirefox-debuginfobefore 0:91.2.0-4.el7_90:91.2.0-4.el7_9
Red Hat:enterprise_linux:7::clientthunderbirdbefore 0:91.2.0-1.el7_90:91.2.0-1.el7_9
Red Hat:enterprise_linux:7::clientthunderbird-debuginfobefore 0:91.2.0-1.el7_90:91.2.0-1.el7_9
Red Hat:enterprise_linux:8::appstreamfirefoxbefore 0:91.2.0-4.el8_40:91.2.0-4.el8_4
Red Hat:enterprise_linux:8::appstreamfirefox-debuginfobefore 0:91.2.0-4.el8_40:91.2.0-4.el8_4
Red Hat:enterprise_linux:8::appstreamfirefox-debugsourcebefore 0:91.2.0-4.el8_40:91.2.0-4.el8_4
Red Hat:enterprise_linux:8::appstreamthunderbirdbefore 0:91.2.0-1.el8_40:91.2.0-1.el8_4
Red Hat:enterprise_linux:8::appstreamthunderbird-debuginfobefore 0:91.2.0-1.el8_40:91.2.0-1.el8_4
Red Hat:enterprise_linux:8::appstreamthunderbird-debugsourcebefore 0:91.2.0-1.el8_40:91.2.0-1.el8_4

+22

Other highest-scoring records for the same primary product.

  • CVE-2020-15254Undefined Behavior in bounded Crossbeam channel
    40Plan
  • CVE-2018-20996An issue was discovered in the crossbeam crate before 0.4.1 for Rust.
    40Plan
  • CVE-2022-23639Improper Restriction of Operations within the Bounds of a Memory Buffer and Race Condition in crossbeam-utils
    32Monitor

Remediation

Which version to upgrade to

Fix versions compiled from the vendor, package registries and Microsoft. Verify the vendor's note before upgrading.

Product / packageFixed versionSource
crates.io:crossbeam-deque0.7.4Package registry (OSV)
crates.io:crossbeam-deque0.8.1Package registry (OSV)
Debian:rust-crossbeam-deque0.7.4-1 · Debian:12Package registry (OSV)
openSUSE:MozillaFirefox91.2.0-lp152.2.67.1 · openSUSE:Leap 15.2Package registry (OSV)
openSUSE:MozillaFirefox-branding-SLE91-9.5.1 · openSUSE:Leap 15.3Package registry (OSV)
openSUSE:MozillaThunderbird91.4.0-lp152.2.52.1 · openSUSE:Leap 15.2Package registry (OSV)
openSUSE:rust-cbindgen0.19.0-lp152.2.7.1 · openSUSE:Leap 15.2Package registry (OSV)
Red Hat:firefox0:91.2.0-4.el8_4 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
Red Hat:firefox-debuginfo0:91.2.0-4.el8_4 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
Red Hat:firefox-debugsource0:91.2.0-4.el8_4 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
Red Hat:thunderbird0:91.2.0-1.el8_4 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
Red Hat:thunderbird-debuginfo0:91.2.0-1.el8_4 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
Red Hat:thunderbird-debugsource0:91.2.0-1.el8_4 · Red Hat:enterprise_linux:8::appstreamPackage registry (OSV)
Rocky Linux:firefox0:91.2.0-4.el8_4 · Rocky Linux:8Package registry (OSV)
Rocky Linux:thunderbird0:91.2.0-1.el8_4 · Rocky Linux:8Package registry (OSV)
SUSE:MozillaFirefox91.2.0-78.143.1 · SUSE:Linux Enterprise Server 11 SP4-LTSSPackage registry (OSV)
SUSE:MozillaFirefox-branding-SLE91-4.19.1 · SUSE:Linux Enterprise High Performance Computing 15-ESPOSPackage registry (OSV)
SUSE:MozillaFirefox-branding-SLED91-21.18.1 · SUSE:Linux Enterprise Server 11 SP4-LTSSPackage registry (OSV)
SUSE:MozillaThunderbird91.4.0-8.45.2 · SUSE:Linux Enterprise Workstation Extension 15 SP2Package registry (OSV)

Exploit status

No known public exploit

No public exploit has been observed yet. That doesn't mean you're safe, only that the bar is a little higher.

Research context

For pentesters and researchers: attack profile, score disagreement, timeline, patch commits, credits, variant and chain candidates, bug bounty scope. All derived from existing data; no exploit code.

Timeline

From publication to today: proof of concept, Metasploit module, CISA KEV and fix record. Dates are as reported by the sources.

No dated events beyond publication.

EPSS, last 120 days

FIRST EPSS daily score; only changes of 0.01 or more are recorded (step chart).

Patch and commit links

Commit, PR and diff links among the references. A starting point for patch-diffing and variant hunting; fixes, not exploits.

No commit or PR link among the references.

Finders, reporters and analysts named in the CNA record. Click a name for that researcher’s other records.

No credits in the CNA record.

Variant candidates

Same product, same weakness class, within 18 months. If the patch missed the root cause, the sibling bug is here.

No nightly-computed relations.

Chain candidates

An authentication bypass and a privilege-requiring bug in the same product, published close together: combined they may become an unauthenticated path.

—

Bug bounty scope

No known public program.

Source: bounty-targets-data (public HackerOne, Bugcrowd, Intigriti, YesWeHack listings).

Technical details

Attack conditions

  • Anyone who can reach it over the internet can trigger it.
  • No account or password is required.
  • No user action is required.
  • No special conditions are required; it is repeatable.

If successful

Confidentiality
high · data can be read
Integrity
high · data or configuration can be modified
Availability
high · the service can be disrupted
Attack vector
Network
Attack complexity
Low
Privileges required
None
User interaction
None
Scope
Unchanged
Confidentiality impact
High
Integrity impact
High
Availability impact
High

CVSS vector

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

nvd-primary

Attack context

MITRE CAPEC attack patterns and ATT&CK techniques for this weakness class (CWE). A starting point for detection rules and threat hunting.

Noroxi analysis

No Noroxi analysis for this record yet

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Change log

  1. Fix✗ → ✓

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References

Vendor advisories and official records. Exploit/PoC links are deliberately left out.

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