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Not in CISA KEV
HIGH severity

CVE-2020-36451 — rcu_cell

HIGHFix: Xudong-Huang/rcu_cell#4

CVE-2020-36451 is a high-severity (CVSS 8.1) CWE-77 vulnerability in rcu_cell. 1 public exploit reference exists, so weaponization risk is real. A fix is available for rcu_cell — see the affected versions and patch details below.

Data races in rcu_cell

Also known asRUSTSEC-2020-0131
Published
Updated
Affected
1 pkg
Patched
1 / 1
Exploits
1 known
Exploitation data as of Oct 9, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
1.2%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs69th percentile — riskier than 69% of all scored CVEsHighest risk
0.01%0.59%1.17%1.75%0.5%1.2%Apr 26Aug 26Oct 26

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

How urgent is this, really

CVE-2020-36451 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.

Where this sits among everything scored

Of 385,987 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
🦀rcu_cell

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

Affected versions of this crate unconditionally implement Send/Sync for RcuCell<T>. This allows users to send T: !Send to other threads (while T enclosed within RcuCell<T>), and allows users to concurrently access T: !Sync by using the APIs of RcuCell<T> that provide access to &T.

This can result in memory corruption caused by data races.

Affected Packages

1 total 1 fixed
EcosystemPackageVulnerable rangeFix
🦀crates.iorcu_cellall versions0.1.9cargo update -p rcu_cell --precise 0.1.9

Affected Products

1 product · 1 configurations
Application
rcu cellrcu_cell_project
≤ 2020-11-14
range
Exploits & PoCs
1

Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.

An issue was discovered in the rcu_cell crate through 2020-11-14 for Rus…

rustsec.orgNVDAug 2021

Detection & mitigation playbook

Open-source dependency

  1. Detect

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

  2. Fix

    Update rcu_cell to 0.1.9 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-36451 is resolved across your whole dependency graph.

  3. 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.

Frequently Asked Questions

Affected versions of this crate unconditionally implement Send/Sync for `RcuCell<T>`. This allows users to send `T: !Send` to other threads (while `T` enclosed within `RcuCell<T>`), and allows users to concurrently access `T: !Sync` by using the APIs of `RcuCell<T>` that provide access to `&T`. This can result in memory corruption caused by data races.
O3 Security · Impact-Aware SCA

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CVE-2020-36451: rcu_cell — Fixed in 0.1.9