CVE-2026-3784 - Vulnerability Details

- wrong proxy connection reuse with credentials

Description

curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a
server, even if the new request uses different credentials for the HTTP proxy.
The proper behavior is to create or use a separate connection.

Published: 2026-03-11

Score: 6.5 Medium

EPSS: < 1% Very Low

KEV: No

Impact:

Action:

Analysis

Analysis and contextual insights are available on OpenCVE Cloud.

Default status is the baseline for the product, each version can override it (e.g. patched versions marked unaffected).

Vendor Product Default status Versions

curl

unaffected

Version	Status	Constraints
`8.18.0`	affected	≤ 8.18.0
`8.17.0`	affected	≤ 8.17.0
`8.16.0`	affected	≤ 8.16.0
`8.15.0`	affected	≤ 8.15.0
`8.14.1`	affected	≤ 8.14.1
`8.14.0`	affected	≤ 8.14.0
`8.13.0`	affected	≤ 8.13.0
`8.12.1`	affected	≤ 8.12.1
`8.12.0`	affected	≤ 8.12.0
`8.11.1`	affected	≤ 8.11.1
`8.11.0`	affected	≤ 8.11.0
`8.10.1`	affected	≤ 8.10.1
`8.10.0`	affected	≤ 8.10.0
`8.9.1`	affected	≤ 8.9.1
`8.9.0`	affected	≤ 8.9.0
`8.8.0`	affected	≤ 8.8.0
`8.7.1`	affected	≤ 8.7.1
`8.7.0`	affected	≤ 8.7.0
`8.6.0`	affected	≤ 8.6.0
`8.5.0`	affected	≤ 8.5.0
`8.4.0`	affected	≤ 8.4.0
`8.3.0`	affected	≤ 8.3.0
`8.2.1`	affected	≤ 8.2.1
`8.2.0`	affected	≤ 8.2.0
`8.1.2`	affected	≤ 8.1.2
`8.1.1`	affected	≤ 8.1.1
`8.1.0`	affected	≤ 8.1.0
`8.0.1`	affected	≤ 8.0.1
`8.0.0`	affected	≤ 8.0.0
`7.88.1`	affected	≤ 7.88.1
`7.88.0`	affected	≤ 7.88.0
`7.87.0`	affected	≤ 7.87.0
`7.86.0`	affected	≤ 7.86.0
`7.85.0`	affected	≤ 7.85.0
`7.84.0`	affected	≤ 7.84.0
`7.83.1`	affected	≤ 7.83.1
`7.83.0`	affected	≤ 7.83.0
`7.82.0`	affected	≤ 7.82.0
`7.81.0`	affected	≤ 7.81.0
`7.80.0`	affected	≤ 7.80.0
`7.79.1`	affected	≤ 7.79.1
`7.79.0`	affected	≤ 7.79.0
`7.78.0`	affected	≤ 7.78.0
`7.77.0`	affected	≤ 7.77.0
`7.76.1`	affected	≤ 7.76.1
`7.76.0`	affected	≤ 7.76.0
`7.75.0`	affected	≤ 7.75.0
`7.74.0`	affected	≤ 7.74.0
`7.73.0`	affected	≤ 7.73.0
`7.72.0`	affected	≤ 7.72.0
`7.71.1`	affected	≤ 7.71.1
`7.71.0`	affected	≤ 7.71.0
`7.70.0`	affected	≤ 7.70.0
`7.69.1`	affected	≤ 7.69.1
`7.69.0`	affected	≤ 7.69.0
`7.68.0`	affected	≤ 7.68.0
`7.67.0`	affected	≤ 7.67.0
`7.66.0`	affected	≤ 7.66.0
`7.65.3`	affected	≤ 7.65.3
`7.65.2`	affected	≤ 7.65.2
`7.65.1`	affected	≤ 7.65.1
`7.65.0`	affected	≤ 7.65.0
`7.64.1`	affected	≤ 7.64.1
`7.64.0`	affected	≤ 7.64.0
`7.63.0`	affected	≤ 7.63.0
`7.62.0`	affected	≤ 7.62.0
`7.61.1`	affected	≤ 7.61.1
`7.61.0`	affected	≤ 7.61.0
`7.60.0`	affected	≤ 7.60.0
`7.59.0`	affected	≤ 7.59.0
`7.58.0`	affected	≤ 7.58.0
`7.57.0`	affected	≤ 7.57.0
`7.56.1`	affected	≤ 7.56.1
`7.56.0`	affected	≤ 7.56.0
`7.55.1`	affected	≤ 7.55.1
`7.55.0`	affected	≤ 7.55.0
`7.54.1`	affected	≤ 7.54.1
`7.54.0`	affected	≤ 7.54.0
`7.53.1`	affected	≤ 7.53.1
`7.53.0`	affected	≤ 7.53.0
`7.52.1`	affected	≤ 7.52.1
`7.52.0`	affected	≤ 7.52.0
`7.51.0`	affected	≤ 7.51.0
`7.50.3`	affected	≤ 7.50.3
`7.50.2`	affected	≤ 7.50.2
`7.50.1`	affected	≤ 7.50.1
`7.50.0`	affected	≤ 7.50.0
`7.49.1`	affected	≤ 7.49.1
`7.49.0`	affected	≤ 7.49.0
`7.48.0`	affected	≤ 7.48.0
`7.47.1`	affected	≤ 7.47.1
`7.47.0`	affected	≤ 7.47.0
`7.46.0`	affected	≤ 7.46.0
`7.45.0`	affected	≤ 7.45.0
`7.44.0`	affected	≤ 7.44.0
`7.43.0`	affected	≤ 7.43.0
`7.42.1`	affected	≤ 7.42.1
`7.42.0`	affected	≤ 7.42.0
`7.41.0`	affected	≤ 7.41.0
`7.40.0`	affected	≤ 7.40.0
`7.39.0`	affected	≤ 7.39.0
`7.38.0`	affected	≤ 7.38.0
`7.37.1`	affected	≤ 7.37.1
`7.37.0`	affected	≤ 7.37.0
`7.36.0`	affected	≤ 7.36.0
`7.35.0`	affected	≤ 7.35.0
`7.34.0`	affected	≤ 7.34.0
`7.33.0`	affected	≤ 7.33.0
`7.32.0`	affected	≤ 7.32.0
`7.31.0`	affected	≤ 7.31.0
`7.30.0`	affected	≤ 7.30.0
`7.29.0`	affected	≤ 7.29.0
`7.28.1`	affected	≤ 7.28.1
`7.28.0`	affected	≤ 7.28.0
`7.27.0`	affected	≤ 7.27.0
`7.26.0`	affected	≤ 7.26.0
`7.25.0`	affected	≤ 7.25.0
`7.24.0`	affected	≤ 7.24.0
`7.23.1`	affected	≤ 7.23.1
`7.23.0`	affected	≤ 7.23.0
`7.22.0`	affected	≤ 7.22.0
`7.21.7`	affected	≤ 7.21.7
`7.21.6`	affected	≤ 7.21.6
`7.21.5`	affected	≤ 7.21.5
`7.21.4`	affected	≤ 7.21.4
`7.21.3`	affected	≤ 7.21.3
`7.21.2`	affected	≤ 7.21.2
`7.21.1`	affected	≤ 7.21.1
`7.21.0`	affected	≤ 7.21.0
`7.20.1`	affected	≤ 7.20.1
`7.20.0`	affected	≤ 7.20.0
`7.19.7`	affected	≤ 7.19.7
`7.19.6`	affected	≤ 7.19.6
`7.19.5`	affected	≤ 7.19.5
`7.19.4`	affected	≤ 7.19.4
`7.19.3`	affected	≤ 7.19.3
`7.19.2`	affected	≤ 7.19.2
`7.19.1`	affected	≤ 7.19.1
`7.19.0`	affected	≤ 7.19.0
`7.18.2`	affected	≤ 7.18.2
`7.18.1`	affected	≤ 7.18.1
`7.18.0`	affected	≤ 7.18.0
`7.17.1`	affected	≤ 7.17.1
`7.17.0`	affected	≤ 7.17.0
`7.16.4`	affected	≤ 7.16.4
`7.16.3`	affected	≤ 7.16.3
`7.16.2`	affected	≤ 7.16.2
`7.16.1`	affected	≤ 7.16.1
`7.16.0`	affected	≤ 7.16.0
`7.15.5`	affected	≤ 7.15.5
`7.15.4`	affected	≤ 7.15.4
`7.15.3`	affected	≤ 7.15.3
`7.15.2`	affected	≤ 7.15.2
`7.15.1`	affected	≤ 7.15.1
`7.15.0`	affected	≤ 7.15.0
`7.14.1`	affected	≤ 7.14.1
`7.14.0`	affected	≤ 7.14.0
`7.13.2`	affected	≤ 7.13.2
`7.13.1`	affected	≤ 7.13.1
`7.13.0`	affected	≤ 7.13.0
`7.12.3`	affected	≤ 7.12.3
`7.12.2`	affected	≤ 7.12.2
`7.12.1`	affected	≤ 7.12.1
`7.12.0`	affected	≤ 7.12.0
`7.11.2`	affected	≤ 7.11.2
`7.11.1`	affected	≤ 7.11.1
`7.11.0`	affected	≤ 7.11.0
`7.10.8`	affected	≤ 7.10.8
`7.10.7`	affected	≤ 7.10.7
`7.10.6`	affected	≤ 7.10.6
`7.10.5`	affected	≤ 7.10.5
`7.10.4`	affected	≤ 7.10.4
`7.10.3`	affected	≤ 7.10.3
`7.10.2`	affected	≤ 7.10.2
`7.10.1`	affected	≤ 7.10.1
`7.10`	affected	≤ 7.10
`7.9.8`	affected	≤ 7.9.8
`7.9.7`	affected	≤ 7.9.7
`7.9.6`	affected	≤ 7.9.6
`7.9.5`	affected	≤ 7.9.5
`7.9.4`	affected	≤ 7.9.4
`7.9.3`	affected	≤ 7.9.3
`7.9.2`	affected	≤ 7.9.2
`7.9.1`	affected	≤ 7.9.1
`7.9`	affected	≤ 7.9
`7.8.1`	affected	≤ 7.8.1
`7.8`	affected	≤ 7.8
`7.7.3`	affected	≤ 7.7.3
`7.7.2`	affected	≤ 7.7.2
`7.7.1`	affected	≤ 7.7.1
`7.7`	affected	≤ 7.7

Configuration 1 [-]

cpe:2.3:a:haxx:curl:*:*:*:*:*:*:*:*

No data.

Vendor Product Confidence Versions

Curl

100%

Version	Status	Scheme	Platform
`8.18.0`	affected	semver	—
`8.17.0`	affected	semver	—
`8.16.0`	affected	semver	—
`8.15.0`	affected	semver	—
`8.14.1`	affected	semver	—
`8.14.0`	affected	semver	—
`8.13.0`	affected	semver	—
`8.12.1`	affected	semver	—
`8.12.0`	affected	semver	—
`8.11.1`	affected	semver	—
`8.11.0`	affected	semver	—
`8.10.1`	affected	semver	—
`8.10.0`	affected	semver	—
`8.9.1`	affected	semver	—
`8.9.0`	affected	semver	—
`8.8.0`	affected	semver	—
`8.7.1`	affected	semver	—
`8.7.0`	affected	semver	—
`8.6.0`	affected	semver	—
`8.5.0`	affected	semver	—
`8.4.0`	affected	semver	—
`8.3.0`	affected	semver	—
`8.2.1`	affected	semver	—
`8.2.0`	affected	semver	—
`8.1.2`	affected	semver	—
`8.1.1`	affected	semver	—
`8.1.0`	affected	semver	—
`8.0.1`	affected	semver	—
`8.0.0`	affected	semver	—
`7.88.1`	affected	semver	—
`7.88.0`	affected	semver	—
`7.87.0`	affected	semver	—
`7.86.0`	affected	semver	—
`7.85.0`	affected	semver	—
`7.84.0`	affected	semver	—
`7.83.1`	affected	semver	—
`7.83.0`	affected	semver	—
`7.82.0`	affected	semver	—
`7.81.0`	affected	semver	—
`7.80.0`	affected	semver	—
`7.79.1`	affected	semver	—
`7.79.0`	affected	semver	—
`7.78.0`	affected	semver	—
`7.77.0`	affected	semver	—
`7.76.1`	affected	semver	—
`7.76.0`	affected	semver	—
`7.75.0`	affected	semver	—
`7.74.0`	affected	semver	—
`7.73.0`	affected	semver	—
`7.72.0`	affected	semver	—
`7.71.1`	affected	semver	—
`7.71.0`	affected	semver	—
`7.70.0`	affected	semver	—
`7.69.1`	affected	semver	—
`7.69.0`	affected	semver	—
`7.68.0`	affected	semver	—
`7.67.0`	affected	semver	—
`7.66.0`	affected	semver	—
`7.65.3`	affected	semver	—
`7.65.2`	affected	semver	—
`7.65.1`	affected	semver	—
`7.65.0`	affected	semver	—
`7.64.1`	affected	semver	—
`7.64.0`	affected	semver	—
`7.63.0`	affected	semver	—
`7.62.0`	affected	semver	—
`7.61.1`	affected	semver	—
`7.61.0`	affected	semver	—
`7.60.0`	affected	semver	—
`7.59.0`	affected	semver	—
`7.58.0`	affected	semver	—
`7.57.0`	affected	semver	—
`7.56.1`	affected	semver	—
`7.56.0`	affected	semver	—
`7.55.1`	affected	semver	—
`7.55.0`	affected	semver	—
`7.54.1`	affected	semver	—
`7.54.0`	affected	semver	—
`7.53.1`	affected	semver	—
`7.53.0`	affected	semver	—
`7.52.1`	affected	semver	—
`7.52.0`	affected	semver	—
`7.51.0`	affected	semver	—
`7.50.3`	affected	semver	—
`7.50.2`	affected	semver	—
`7.50.1`	affected	semver	—
`7.50.0`	affected	semver	—
`7.49.1`	affected	semver	—
`7.49.0`	affected	semver	—
`7.48.0`	affected	semver	—
`7.47.1`	affected	semver	—
`7.47.0`	affected	semver	—
`7.46.0`	affected	semver	—
`7.45.0`	affected	semver	—
`7.44.0`	affected	semver	—
`7.43.0`	affected	semver	—
`7.42.1`	affected	semver	—
`7.42.0`	affected	semver	—
`7.41.0`	affected	semver	—
`7.40.0`	affected	semver	—
`7.39.0`	affected	semver	—
`7.38.0`	affected	semver	—
`7.37.1`	affected	semver	—
`7.37.0`	affected	semver	—
`7.36.0`	affected	semver	—
`7.35.0`	affected	semver	—
`7.34.0`	affected	semver	—
`7.33.0`	affected	semver	—
`7.32.0`	affected	semver	—
`7.31.0`	affected	semver	—
`7.30.0`	affected	semver	—
`7.29.0`	affected	semver	—
`7.28.1`	affected	semver	—
`7.28.0`	affected	semver	—
`7.27.0`	affected	semver	—
`7.26.0`	affected	semver	—
`7.25.0`	affected	semver	—
`7.24.0`	affected	semver	—
`7.23.1`	affected	semver	—
`7.23.0`	affected	semver	—
`7.22.0`	affected	semver	—
`7.21.7`	affected	semver	—
`7.21.6`	affected	semver	—
`7.21.5`	affected	semver	—
`7.21.4`	affected	semver	—
`7.21.3`	affected	semver	—
`7.21.2`	affected	semver	—
`7.21.1`	affected	semver	—
`7.21.0`	affected	semver	—
`7.20.1`	affected	semver	—
`7.20.0`	affected	semver	—
`7.19.7`	affected	semver	—
`7.19.6`	affected	semver	—
`7.19.5`	affected	semver	—
`7.19.4`	affected	semver	—
`7.19.3`	affected	semver	—
`7.19.2`	affected	semver	—
`7.19.1`	affected	semver	—
`7.19.0`	affected	semver	—
`7.18.2`	affected	semver	—
`7.18.1`	affected	semver	—
`7.18.0`	affected	semver	—
`7.17.1`	affected	semver	—
`7.17.0`	affected	semver	—
`7.16.4`	affected	semver	—
`7.16.3`	affected	semver	—
`7.16.2`	affected	semver	—
`7.16.1`	affected	semver	—
`7.16.0`	affected	semver	—
`7.15.5`	affected	semver	—
`7.15.4`	affected	semver	—
`7.15.3`	affected	semver	—
`7.15.2`	affected	semver	—
`7.15.1`	affected	semver	—
`7.15.0`	affected	semver	—
`7.14.1`	affected	semver	—
`7.14.0`	affected	semver	—
`7.13.2`	affected	semver	—
`7.13.1`	affected	semver	—
`7.13.0`	affected	semver	—
`7.12.3`	affected	semver	—
`7.12.2`	affected	semver	—
`7.12.1`	affected	semver	—
`7.12.0`	affected	semver	—
`7.11.2`	affected	semver	—
`7.11.1`	affected	semver	—
`7.11.0`	affected	semver	—
`7.10.8`	affected	semver	—
`7.10.7`	affected	semver	—
`7.10.6`	affected	semver	—
`7.10.5`	affected	semver	—
`7.10.4`	affected	semver	—
`7.10.3`	affected	semver	—
`7.10.2`	affected	semver	—
`7.10.1`	affected	semver	—
`7.10`	affected	generic	—
`7.9.8`	affected	semver	—
`7.9.7`	affected	semver	—
`7.9.6`	affected	semver	—
`7.9.5`	affected	semver	—
`7.9.4`	affected	semver	—
`7.9.3`	affected	semver	—
`7.9.2`	affected	semver	—
`7.9.1`	affected	semver	—
`7.9`	affected	generic	—
`7.8.1`	affected	semver	—
`7.8`	affected	generic	—
`7.7.3`	affected	semver	—
`7.7.2`	affected	semver	—
`7.7.1`	affected	semver	—
`7.7`	affected	generic	—

Found an issue or want to improve our Enrichment? You can suggest it directly by opening an issue on our dedicated GitHub repository .

Remediation

No vendor fix or workaround currently provided.

Additional remediation guidance may be available on OpenCVE Cloud.

Tracking

Sign in to view the affected projects.

Advisories

Source	ID	Title
Ubuntu USN	USN-8084-1	curl vulnerabilities
Ubuntu USN	USN-8099-1	curl vulnerabilities

No CVSS v4.0

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction None

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00022.

Exploitation none

Automatable yes

Technical Impact partial

References

Link	Providers
http://www.openwall.com/lists/oss-security/2026/03/11/3
https://curl.se/docs/CVE-2026-3784.html
https://curl.se/docs/CVE-2026-3784.json
https://hackerone.com/reports/3584903
https://nvd.nist.gov/vuln/detail/CVE-2026-3784
https://www.cve.org/CVERecord?id=CVE-2026-3784

History

Fri, 13 Mar 2026 00:15:00 +0000

Type	Values Removed	Values Added
References		https://nvd.nist.gov/vuln/detail/CVE-2026-3784 https://www.cve.org/CVERecord?id=CVE-2026-3784
Metrics	threat_severity `None`	threat_severity `Moderate`

Thu, 12 Mar 2026 14:15:00 +0000

Type	Values Removed	Values Added
First Time appeared		Haxx Haxx curl
CPEs		cpe:2.3:a:haxx:curl::::::::
Vendors & Products		Haxx Haxx curl

Thu, 12 Mar 2026 10:15:00 +0000

Type	Values Removed	Values Added
First Time appeared		Curl Curl curl
Vendors & Products		Curl Curl curl

Wed, 11 Mar 2026 16:15:00 +0000

Type	Values Removed	Values Added
Weaknesses		CWE-305
Metrics		cvssV3_1 `{'score': 6.5, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N'}` ssvc `{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'partial'}, 'version': '2.0.3'}`

Wed, 11 Mar 2026 11:30:00 +0000

Type	Values Removed	Values Added
References		http://www.openwall.com/lists/oss-security/2026/03/11/3

Wed, 11 Mar 2026 10:30:00 +0000

Type	Values Removed	Values Added
Description		curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP proxy. The proper behavior is to create or use a separate connection.
Title		wrong proxy connection reuse with credentials
References		https://curl.se/docs/CVE-2026-3784.html https://curl.se/docs/CVE-2026-3784.json https://hackerone.com/reports/3584903

Subscriptions

Curl Curl

Haxx Curl

MITRE

Status: PUBLISHED

Assigner: curl

Published: 2026-03-11T10:09:21.418Z

Updated: 2026-03-11T15:48:41.725Z

Reserved: 2026-03-08T05:09:52.279Z

Link: CVE-2026-3784

Vulnrichment

Updated: 2026-03-11T10:16:32.844Z

NVD

Status : Analyzed

Published: 2026-03-11T11:16:00.437

Modified: 2026-03-12T14:09:50.470

Link: CVE-2026-3784

Redhat

Severity : Moderate

Publid Date: 2026-03-11T10:09:21Z

Links: CVE-2026-3784 - Bugzilla

OpenCVE Enrichment

Updated: 2026-03-20T14:37:24Z

Weaknesses

CWE-305

Tracking

Attack Vector Network

Attack Complexity Low

Privileges Required None

Scope Unchanged

Confidentiality Impact Low

Integrity Impact Low

Availability Impact None

User Interaction None

Exploitation none

Automatable yes

Technical Impact partial

Subscriptions

JSON object

JSON object

JSON object

JSON object

JSON object