How severe is CVE-2020-35879?

CVE-2020-35879 has a CVSS score of 9.8/10, rated CRITICAL. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-35879?

CVE-2020-35879 affects the following packages: rulinalg (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2020-35879?

No patched version of rulinalg has shipped for CVE-2020-35879 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

How do I detect CVE-2020-35879 in my crates.io dependencies?

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

How do I mitigate CVE-2020-35879 if there is no patch (or I can't update yet)?

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.

Is CVE-2020-35879 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2020-35879, including 1 in-the-wild exploitation observed on GitHub and other sources. Treat this as actively exploitable and prioritize patching immediately. All exploit code should only be run in an isolated sandbox environment for research or authorized testing — never against production systems without explicit written authorization.

What is the EPSS score for CVE-2020-35879?

CVE-2020-35879 has an EPSS (Exploit Prediction Scoring System) score of 1.7%, placing it in the 76th percentile of all CVEs. EPSS is maintained by FIRST.org and estimates the probability that a vulnerability will be exploited in the wild within the next 30 days. This score indicates relatively lower exploitation probability, though the CVSS severity should still guide your patching priority.

When was CVE-2020-35879 published, and has it been updated?

CVE-2020-35879 was published on August 25, 2021 and was last updated on November 8, 2023. Advisory data evolves as severity scores, affected ranges, and exploit intelligence are revised — always check the latest version of the advisory before acting.

🦀

🦀 crates.io

Not in CISA KEV

CRITICAL severity

CVE-2020-35879 — rulinalg

CRITICAL

CVE-2020-35879 is a critical-severity (CVSS 9.8) vulnerability in rulinalg. 1 public exploit reference exists, so weaponization risk is real. No vendor fix is recorded yet; mitigation options are listed below.

Data races in rulinalg

Also known asRUSTSEC-2020-0023

Published

Aug 25, 2021

Updated

Nov 8, 2023

Affected

1 pkg

Patched

See advisory

Exploits

1 known

Exploitation data as of Oct 11, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

1.7%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs76th percentile — riskier than 76% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2020-35879 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

🦀rulinalg

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

The affected version of rulinalg has incorrect lifetime boundary definitions for RowMut::raw_slice and RowMut::raw_slice_mut. They do not conform with Rust's borrowing rule and allows the user to create multiple mutable references to the same location. This may result in unexpected calculation result and data race if both references are used at the same time.

Affected Packages

1 total

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`rulinalg`	≥ 0.4.0	No fix

Affected Products

1 product · 1 configurations

Application

rulinalgrulinalg_project

1 version

0.4.1

Exploits & PoCs

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 rulinalg crate through 2020-02-11 for Rus…

rustsec.orgNVDJan 2021

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for rulinalg, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Remediation status
No patched version of rulinalg has shipped for CVE-2020-35879 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.
Mitigate without a patch
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

O3 Security · Impact-Aware SCA

Is CVE-2020-35879 in your dependencies?

Find it across crates.io, including transitive dependencies.

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