CVE-2020-36208

mediumpriority · track · 31EPSS 0.004 · 38 %ileEUUS
grimoire priorityP3 · Track
Exploitable?
—
no known exploitation
Likely / severe?
0.44% (38th) EPSS
CVSS 4.6 · medium
Is it mine?
4 products
Check your exposure
Who says so?
4 sources
cnnvd · enisa_euvd · osv · nvd

EPSS · scored 2026-10-27

An issue was discovered in the conquer-once crate before 0.3.2 for Rust. Thread crossing can occur for a non-Send but Sync type, leading to memory corruption.

01

cvss

Technical severity, 0–10. One row per scoring source.

7.8
010

base score 0–10 · higher = more severe · hover a vector to decode⚠ sources disagree · medium–high · 4.6–7.8

v2.04.6mediumAV:L/AC:L/Au:N/C:P/I:P/A:Pprimary · NVD / NIST USexploitability 3.9 · impact 6.4
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hprimary · NVD / NIST USexploitability 1.8 · impact 5.9
v3.17.8highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:Hsecondary · OSV
v3.17.1highCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H/E:Usecondary · CVSS-BT (t0sche)
02

weaknesses

The CWE weakness classes this flaw belongs to.

CWE-662USprimaryCWE-787USprimaryCWE-662USCWE-787US
03

affected products (4)

Products and version ranges known to be affected.

04

advisories (2)

Vendor and ecosystem advisories describing this.

  • GHSA-3jc5-5hc5-33gjData races in conquer-once2021-08-25ghsa · osvUS

    Affected versions of conquer-once implements Sync for its OnceCell type without restricting it to Sendable types. This allows non-Send but Sync types such as MutexGuard to be sent across threads leading to undefined behavior and memory corruption in concurrent programs. The issue was fixed by adding a Send constraint to OnceCell.

  • RUSTSEC-2020-0101conquer-once's OnceCell lacks Send bound for its Sync trait.2020-12-22vendor · osvUS

    Affected versions of `conquer-once` implements `Sync` for its `OnceCell` type without restricting it to `Send`able types. This allows non-`Send` but `Sync` types such as `MutexGuard` to be sent across threads leading to undefined behavior and memory corruption in concurrent programs. The issue was fixed by adding a `Send` constraint to `OnceCell`.

05

also known as (5)

Other names and identifiers for this entity.

06

sources

Which sources assert this record, and when.

cnnvdenisa_euvdosvnvdNVDCVE.orgMITRE
published 2021-01-26modified 2026-06-17
08

references (5)

External citations — patches, advisories, analysis.

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