What is CVE-2020-36209?

Affected versions of this crate implemented Sync for LateStatic with T: Send, so that it is possible to create a data race to a type T: Send + !Sync (e.g. Cell ). This can result in a memory corruption or other kinds of undefined behavior. The flaw was corrected in commit 11f396c by replacing the T: Send bound to T: Sync bound in the Sync impl for LateStatic .

How severe is CVE-2020-36209?

CVE-2020-36209 has a CVSS score of 7/10, rated HIGH. Immediate patching is strongly recommended.

Which packages are affected by CVE-2020-36209?

CVE-2020-36209 affects the following packages: late-static (crates.io). Ecosystems affected: crates.io.

How do I fix CVE-2020-36209?

Update late-static to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-36209 is resolved across your whole dependency graph.

How do I detect CVE-2020-36209 in my crates.io dependencies?

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

How do I mitigate CVE-2020-36209 if there is no patch (or I can't update yet)?

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.

Is CVE-2020-36209 actively exploited in the wild?

Yes. There are 1 known exploit references for CVE-2020-36209, 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-2020-36209?

CVE-2020-36209 has an EPSS (Exploit Prediction Scoring System) score of 0.4%, placing it in the 27th 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-2020-36209 published, and has it been updated?

CVE-2020-36209 was published on January 26, 2021 and was last updated on July 9, 2026. 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

HIGH severity

CVE-2020-36209 — late-static

HIGHFix: Richard-W/late-static@11f396c

CVE-2020-36209 is a high-severity (CVSS 7) remote code execution vulnerability in late-static. 1 public exploit reference exists, so weaponization risk is real. A fix is available for late-static — see the affected versions and patch details below.

Data races in late-static

Also known asGHSA-wr55-mf5c-hhwmRUSTSEC-2020-0102

Published

Jan 26, 2021

Updated

Jul 9, 2026

Affected

1 pkg

Patched

1 / 1

Exploits

1 known

Exploitation data as of Oct 7, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗

0.4%probability of exploitation in next 30 days

Lower Risk0.00%

Lower risk than most CVEs27th percentile — riskier than 27% of all scored CVEsHighest risk

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

How urgent is this, really

CVE-2020-36209 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

🦀late-static

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 implemented Sync for LateStatic with T: Send, so that it is possible to create a data race to a type T: Send + !Sync (e.g. Cell<T>).

This can result in a memory corruption or other kinds of undefined behavior.

The flaw was corrected in commit 11f396c by replacing the T: Send bound to T: Sync bound in the Sync impl for LateStatic<T>.

Affected Packages

1 total 1 fixed

Ecosystem	Package	Vulnerable range	Fix
🦀crates.io	`late-static`	all versions	0.4.0`cargo update -p late-static --precise 0.4.0`

Affected Products

1 product · 1 configurations

Application

late-staticlate-static_project

< 0.4.0

range

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 late-static crate before 0.4.0 for Rust. …

rustsec.orgNVDFeb 2021

Detection & mitigation playbook

Open-source dependency

Detect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for late-static, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update late-static to 0.4.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-36209 is resolved across your whole dependency graph.
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 implemented Sync for LateStatic with T: Send, so that it is possible to create a data race to a type T: Send + !Sync (e.g. Cell<T>). This can result in a memory corruption or other kinds of undefined behavior. The flaw was corrected in commit 11f396c by replacing the T: Send bound to T: Sync bound in the Sync impl for LateStatic<T>.

O3 Security · Impact-Aware SCA

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