How severe is CVE-2020-35902?

CVE-2020-35902 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2020-35902 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2020-35902?

CVE-2020-35902 affects Actix Actix-codec. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2020-35902?

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-2020-35902 published?

CVE-2020-35902 was published on 2020-12-31 and last updated on 2026-06-17.

CVE-2020-35902

CVE-2020-35902 is a critical-severity vulnerability in Actix Actix-codec with a CVSS 3.x base score of 9.8. 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 9.8)
CVSS v2: 7.5
EPSS exploit prediction: 2% (73rd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-416
Affected product: Actix Actix-codec
Published: 2020-12-31
Last modified: 2026-06-17

Description

An issue was discovered in the actix-codec crate before 0.3.0-beta.1 for Rust. There is a use-after-free in Framed.

Frequently asked questions

What is CVE-2020-35902?: An issue was discovered in the actix-codec crate before 0.3.0-beta.1 for Rust. There is a use-after-free in Framed.
How severe is CVE-2020-35902?: CVE-2020-35902 has a CVSS 3.x base score of 9.8, rated critical severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2020-35902 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (73rd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2020-35902?: CVE-2020-35902 affects Actix Actix-codec. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2020-35902?: 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-2020-35902 published?: CVE-2020-35902 was published on 2020-12-31 and last updated on 2026-06-17.

References

https://rustsec.org/advisories/RUSTSEC-2020-0049.html

Affected products (1)

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

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