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HIGH severity

CVE-2020-36435 — ruspiro-singleton

HIGHFix: RusPiRo/ruspiro-singleton#11

CVE-2020-36435 is a high-severity (CVSS 8.1) CWE-362 vulnerability in ruspiro-singleton. A fix is available for ruspiro-singleton — see the affected versions and patch details below.

Data race in ruspiro-singleton

Also known asRUSTSEC-2020-0115
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
None indexed
Exploitation data as of Oct 8, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.8%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs54th percentile — riskier than 54% of all scored CVEsHighest risk
0.00%0.42%0.84%1.27%0.3%0.8%Apr 26Aug 26Oct 26

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

How urgent is this, really

CVE-2020-36435 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

1 pkg affected
🦀ruspiro-singleton

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

Singleton<T> is meant to be a static object that can be initialized lazily. In order to satisfy the requirement that static items must implement Sync, Singleton implemented both Sync and Send unconditionally.

This allows for a bug where non-Sync types such as Cell can be used in singletons and cause data races in concurrent programs.

The flaw was corrected in commit b0d2bd20e by adding trait bounds, requiring the contaiend type to implement Sync.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.ioruspiro-singletonall versions0.4.1cargo update -p ruspiro-singleton --precise 0.4.1

Affected Products

1 product · 1 configurations
Application
ruspiro-singletonruspiro-singleton_project
< 0.4.1
range

Detection & mitigation playbook

Open-source dependency

  1. Detect

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

  2. Fix

    Update ruspiro-singleton to 0.4.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-36435 is resolved across your whole dependency graph.

  3. 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

`Singleton<T>` is meant to be a static object that can be initialized lazily. In order to satisfy the requirement that `static` items must implement `Sync`, `Singleton` implemented both `Sync` and `Send` unconditionally. This allows for a bug where non-`Sync` types such as `Cell` can be used in singletons and cause data races in concurrent programs. The flaw was corrected in commit `b0d2bd20e` by adding trait bounds, requiring the contaiend type to implement `Sync`.
O3 Security · Impact-Aware SCA

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CVE-2020-36435: ruspiro-singleton — Fixed in 0.4.1