cURL up to 8.18.0 HTTP Proxy Connection authentication bypass

CVSS Meta Temp Score
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Current Exploit Price (≈)
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CTI Interest Score
Our Cyber Threat Intelligence team is monitoring different web sites, mailing lists, exploit markets and social media networks. The CTI Interest Score identifies the interest of attackers and the security community for this specific vulnerability in real-time. A high score indicates an elevated risk to be targeted for this vulnerability.
5.0$0-$5k0.00

Summaryinfo

A vulnerability described as problematic has been identified in cURL. This issue affects some unknown processing of the component HTTP Proxy Connection Handler. The manipulation results in authentication bypass. This vulnerability is identified as CVE-2026-3784. The attack can be executed remotely. There is not any exploit available. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in cURL. It has been classified as problematic. Affected is an unknown code block of the component HTTP Proxy Connection Handler. The manipulation with an unknown input leads to a authentication bypass vulnerability. CWE is classifying the issue as CWE-305. The authentication algorithm is sound, but the implemented mechanism can be bypassed as the result of a separate weakness that is primary to the authentication error. This is going to have an impact on confidentiality. CVE summarizes:

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.

The weakness was released by Muhamad Arga Reksapati. The advisory is shared for download at curl.se. This vulnerability is traded as CVE-2026-3784 since 03/08/2026. The exploitability is told to be difficult. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are neither technical details nor an exploit publicly available.

The vulnerability scanner Nessus provides a plugin with the ID 302096 (SUSE SLES15 / openSUSE 15 Security Update : curl (SUSE-SU-2026:0885-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading eliminates this vulnerability.

The vulnerability is also documented in the databases at Tenable (302096) and CERT Bund (WID-SEC-2026-0690). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Affected

  • Open Source cURL

Productinfo

Type

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 5.1
VulDB Meta Temp Score: 5.0

VulDB Base Score: 3.7
VulDB Temp Score: 3.6
VulDB Vector: 🔒
VulDB Reliability: 🔍

ADP CISA Base Score: 6.5
ADP CISA Vector: 🔒

CVSSv2info

AVACAuCIA
💳💳💳💳💳💳
💳💳💳💳💳💳
💳💳💳💳💳💳
VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Authentication bypass
CWE: CWE-305 / CWE-287
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined

EPSS Score: 🔒
EPSS Percentile: 🔒

Price Prediction: 🔍
Current Price Estimation: 🔒

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Nessus ID: 302096
Nessus Name: SUSE SLES15 / openSUSE 15 Security Update : curl (SUSE-SU-2026:0885-1)

Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Timelineinfo

03/08/2026 CVE reserved
03/11/2026 +3 days Advisory disclosed
03/11/2026 +0 days VulDB entry created
03/14/2026 +3 days VulDB entry last update

Sourcesinfo

Advisory: curl.se
Researcher: Muhamad Arga Reksapati
Status: Confirmed

CVE: CVE-2026-3784 (🔒)
GCVE (CVE): GCVE-0-2026-3784
GCVE (VulDB): GCVE-100-350376
CERT Bund: WID-SEC-2026-0690 - cURL: Mehrere Schwachstellen

Entryinfo

Created: 03/11/2026 12:50
Updated: 03/14/2026 06:29
Changes: 03/11/2026 12:50 (54), 03/12/2026 01:19 (7), 03/13/2026 19:06 (2), 03/14/2026 06:29 (12)
Complete: 🔍
Cache ID: 216::103

VulDB is the best source for vulnerability data and more expert information about this specific topic.

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