How severe is CVE-2021-38512?

CVE-2021-38512 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-38512 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-38512?

CVE-2021-38512 primarily affects Actix Actix-http. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-38512?

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

When was CVE-2021-38512 published?

CVE-2021-38512 was published on 2021-08-10 and last updated on 2026-06-17.

CVE-2021-38512

CVE-2021-38512 is a high-severity vulnerability in Actix Actix-http with a CVSS 3.x base score of 7.5. 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-444.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (76th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-444
Affected product: Actix Actix-http
Published: 2021-08-10
Last modified: 2026-06-17

Description

An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.

Frequently asked questions

What is CVE-2021-38512?: An issue was discovered in the actix-http crate before 3.0.0-beta.9 for Rust. HTTP/1 request smuggling (aka HRS) can occur, potentially leading to credential disclosure.
How severe is CVE-2021-38512?: CVE-2021-38512 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-38512 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (76th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-38512?: CVE-2021-38512 primarily affects Actix Actix-http. In total, 11 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-38512?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-38512 published?: CVE-2021-38512 was published on 2021-08-10 and last updated on 2026-06-17.

References

Affected products (11)

cpe:2.3:a:actix:actix-http:*:*:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:-:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:beta1:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:beta2:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:beta3:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:beta4:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:beta5:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:beta6:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:beta7:*:*:*:rust:*:*
cpe:2.3:a:actix:actix-http:3.0.0:beta8:*:*:*:rust:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

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