Medium severity · published Mar 11, 2026
CVE-2026-3784
wrong proxy connection reuse with credentials
6.5
CVSS
0.4%
EPSS
No
On KEV
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:N
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Confidentiality
Low
Integrity
Low
Availability
None
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)0.4% · higher than 36% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
CU
curl · curl
7.7.0 before 8.14.2; 8.15.0 before 8.16.1; 8.17.0 before 8.19.0; a1d6ad26100bc493c7b04f1301b1634b7f5aa8b4 before 5f13a7645e565c5c1a06f3ef86e97afb856fb364; 8.18.0; 8.17.0; +34 more · source: vendor, NVD
RR
RUGGEDCOM RST2428P · Siemens
before V4.0 · source: CISA
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2026-3784
CVE.org
https://www.cve.org/CVERecord?id=CVE-2026-3784
Patch
https://curl.se/docs/CVE-2026-3784.html
Vendor Advisory
https://curl.se/docs/CVE-2026-3784.json
Exploit
https://hackerone.com/reports/3584903
Mailing List
http://www.openwall.com/lists/oss-security/2026/03/11/3
cert-portal.siemens.com
https://cert-portal.siemens.com/productcert/html/ssa-253495.html
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