How severe is CVE-2020-35898?

CVE-2020-35898 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.

Is CVE-2020-35898 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-35898?

CVE-2020-35898 affects Actix Actix-utils. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-35898?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

When was CVE-2020-35898 published?

CVE-2020-35898 was published on 2020-12-31 and last updated on 2026-06-17.

CVE-2020-35898

CVE-2020-35898 is a critical-severity vulnerability in Actix Actix-utils with a CVSS 3.x base score of 9.1. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-416.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 1% (69th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-416
Affected product: Actix Actix-utils
Published: 2020-12-31
Last modified: 2026-06-17

Description

An issue was discovered in the actix-utils crate before 2.0.0 for Rust. The Cell implementation allows obtaining more than one mutable reference to the same data.

Frequently asked questions

What is CVE-2020-35898?: An issue was discovered in the actix-utils crate before 2.0.0 for Rust. The Cell implementation allows obtaining more than one mutable reference to the same data.
How severe is CVE-2020-35898?: CVE-2020-35898 has a CVSS 3.x base score of 9.1, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is none, integrity high, and availability high.
Is CVE-2020-35898 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (69th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-35898?: CVE-2020-35898 affects Actix Actix-utils. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-35898?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
When was CVE-2020-35898 published?: CVE-2020-35898 was published on 2020-12-31 and last updated on 2026-06-17.

References

https://rustsec.org/advisories/RUSTSEC-2020-0045.html

Affected products (1)

cpe:2.3:a:actix:actix-utils:*:*:*:*:*:rust:*:*

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