How severe is CVE-2021-41945?

CVE-2021-41945 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 high, integrity high, and availability none.

Is CVE-2021-41945 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-41945?

CVE-2021-41945 affects Encode Httpx. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-41945?

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-2021-41945 published?

CVE-2021-41945 was published on 2022-04-28 and last updated on 2026-07-09.

CVE-2021-41945

Q: What is CVE-2021-41945?

Encode OSS httpx < 0.23.0 is affected by improper input validation in `httpx.URL`, `httpx.Client` and some functions using `httpx.URL.copy_with`.

CVE-2021-41945 is a critical-severity vulnerability in Encode Httpx 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-20.

Key facts

Severity: Critical (CVSS 3.x base score 9.1)
CVSS v2: 6.4
EPSS exploit prediction: 2% (82nd percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-20
Affected product: Encode Httpx
Published: 2022-04-28
Last modified: 2026-07-09

Description

Encode OSS httpx < 0.23.0 is affected by improper input validation in `httpx.URL`, `httpx.Client` and some functions using `httpx.URL.copy_with`.

Frequently asked questions

What is CVE-2021-41945?: Encode OSS httpx < 0.23.0 is affected by improper input validation in `httpx.URL`, `httpx.Client` and some functions using `httpx.URL.copy_with`.
How severe is CVE-2021-41945?: CVE-2021-41945 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 high, integrity high, and availability none.
Is CVE-2021-41945 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (82nd percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-41945?: CVE-2021-41945 affects Encode Httpx. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-41945?: 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-2021-41945 published?: CVE-2021-41945 was published on 2022-04-28 and last updated on 2026-07-09.

References

Affected products (1)

cpe:2.3:a:encode:httpx:*:*:*:*:*:python:*:*

Other CWE-20 (Improper Input Validation) vulnerabilities

CVE-2026-77554 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi…
CVE-2026-77537 — Critical (CVSS 10.0): A malicious actor with access to the network could exploit an Improper Input Validation vulnerability found in UniFi…
CVE-2026-48056 — Critical (CVSS 10.0): Streambert is a cross-platform Electron Desktop App to stream and download video content. Versions prior to 2.5.0…
CVE-2026-33267 — Critical (CVSS 10.0): Improper Input Validation vulnerability in Apache Traffic Server. This issue affects Apache Traffic Server: from 9.2.0…
CVE-2026-47668 — Critical (CVSS 10.0): DbGate is cross-platform database manager. In versions 7.1.8 and prior, DbGate's JSON script runner (`POST…
CVE-2026-16117 — Critical (CVSS 10.0): Impact: @fastify/http-proxy versions up to and including 11.5.0 fail to rewrite the request prefix when the prefix…

Browse all CWE-20 (Improper Input Validation) vulnerabilities →