CVE-2021-41945

Exp

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`.

Published: 2022-04-28 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2021-41945 is rated High Exploit Risk (80.3/100): CVSS Critical severity, with medium exploitation likelihood (EPSS 2.05%). 3 public exploit reference(s) are indexed (Exploit-DB). EPSS rose +1.33% over the last day, indicating growing attacker interest. Public exploits are available—assess exposure, apply mitigations, and prioritize patching.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Public exploit references (Exploit-DB) for CVE-2021-41945

EDB-ID Source Kind Published Link
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗
— nvd_ref exploit_tag Exploit-DB ↗

Exploit prediction scoring system (EPSS) score for CVE-2021-41945

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2026-06-15 0.72% 2.05% +1.33%
2 2025-11-21 0.52% 0.72% +0.20%
3 2025-11-18 — 0.52% —

Full EPSS history (13 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2021-41945

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
9.1 3.1 CRITICAL
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N Click to expand
Attack vector (AV:N)
Could be attacked over the internet or any normal routed network—not just someone sitting at the machine.
Attack complexity (AC:L)
Once they can reach the bug, pulling it off is straightforward—no weird race conditions or rare setup.
Privileges required (PR:N)
No account or special rights needed—anonymous or random user is enough.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:N)
Service keeps running; no real outage angle.
 3.9 5.2 [email protected]
6.4 2.0 MEDIUM
AV:N/AC:L/Au:N/C:P/I:P/A:N Click to expand
Access vector (AV:N)
Can be exploited remotely over network reachability.
Access complexity (AC:L)
Exploitation conditions are straightforward and predictable.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:N)
No availability impact.
 10.0 4.9 [email protected]

Weakness enumeration for CVE-2021-41945

GitHub Security Advisory for CVE-2021-41945

GHSA-h8pj-cxx2-jfg2 · Severity: critical · Ecosystem: pip — Improper Input Validation in httpx

OS Trackers for CVE-2021-41945

vendor priority summary link
debian not yet assigned CVE-2021-41945 not yet assigned priority: Debian including 1 source packages (httpx), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 4, open 1. https://security-tracker.debian.org/tracker/CVE-2021-41945
ubuntu medium CVE-2021-41945 medium priority: Ubuntu including 1 source packages (httpx), 10 status rows across 10 suites (impish, jammy, kinetic, lunar, mantic, noble, oracular, plucky, questing, upstream): ignored 5, needs-triage 3, not-affected 2. https://ubuntu.com/security/CVE-2021-41945

Affected software / configurations for CVE-2021-41945

Vendor Product Version Raw CPE
encode httpx < 0.23.0 cpe:2.3:a:encode:httpx:*:*:*:*:*:python:*:*

References for CVE-2021-41945

URL Tags
http://encode.com Vendor Advisory
https://gist.github.com/lebr0nli/4edb76bbd3b5ff993cf44f2fbce5e571 Exploit Third Party Advisory
https://github.com/encode/httpx Product Third Party Advisory
https://github.com/encode/httpx/discussions/1831 Exploit Issue Tracking Third Party Advisory
https://github.com/encode/httpx/issues/2184 Exploit Issue Tracking Third Party Advisory
https://github.com/encode/httpx/releases/tag/0.23.0 Release Notes Third Party Advisory
cvelogic Threat Intelligence