CVE-2026-3784Authentication Bypass by Primary Weakness in Curl

Severity
6.5MEDIUMNVD
EPSS
0.0%
top 96.34%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedMar 11
Latest updateMar 16

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.

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:NExploitability: 3.9 | Impact: 2.5

Affected Packages3 packages

NVDhaxx/curl7.78.18.0
Debianhaxx/curl< 8.19.0-1
CVEListV5curl/curl8.18.08.18.0+190

Patches

🔴Vulnerability Details

5
OSV
curl vulnerabilities2026-03-16
CVEList
wrong proxy connection reuse with credentials2026-03-11
OSV
CVE-2026-3784: curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP2026-03-11
GHSA
GHSA-5q3w-6p3j-mw6p: curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a server, even if the new request uses different credentials for the HTTP2026-03-11
OSV
curl vulnerabilities2026-03-11

📋Vendor Advisories

5
Ubuntu
curl vulnerabilities2026-03-16
Red Hat
curl: curl: Unauthorized access due to improper HTTP proxy connection reuse2026-03-11
Ubuntu
curl vulnerabilities2026-03-11
Microsoft
wrong proxy connection reuse with credentials2026-03-10
Debian
CVE-2026-3784: curl - curl would wrongly reuse an existing HTTP proxy connection doing CONNECT to a se...2026

🕵️Threat Intelligence

1
Wiz
CVE-2026-3784 Impact, Exploitability, and Mitigation Steps | Wiz

💬Community

3
HackerOne
CVE-2026-3784: wrong proxy connection reuse with credentials2026-03-11
Bugzilla
CVE-2026-3784 curl: curl: Unauthorized access due to improper HTTP proxy connection reuse [fedora-43]2026-03-11
Bugzilla
CVE-2026-3784 curl: curl: Unauthorized access due to improper HTTP proxy connection reuse [fedora-42]2026-03-11
CVE-2026-3784 — Haxx Curl vulnerability | cvebase