CVE-2020-35928 — concread
MEDIUMCVE-2020-35928 is a medium-severity (CVSS 4.7) CWE-362 vulnerability in concread. 1 public exploit reference exists, so weaponization risk is real. A fix is available for concread — see the affected versions and patch details below.
Data races in concread
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2020-35928 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,738 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
concreadReal-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
An issue was discovered in the concread crate before 0.2.6 for Rust. Attackers can cause an ARCache<K,V> data race by sending types that do not implement Send/Sync.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🦀crates.io | concread | all versions | 0.2.6cargo update -p concread --precise 0.2.6 |
Affected Products
concreadconcread_projectResearch 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 concread, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update concread to 0.2.6 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-35928 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.
Frequently Asked Questions
Is CVE-2020-35928 in your dependencies?
Find it across crates.io, including transitive dependencies.