Reference page — cumulative record through Sunday, October 4, 2026 UTC. Reference pages update as the archive grows; only dated daily editions are immutable pages of record.

CVE-2026-3784

CVE-2026-3784MEDIUM

curl curl — wrong proxy connection reuse with credentials

  AV  AC  PR  UI  S  C  I  A   CVSS    EPSS   %ile   KEV
   N   L   N   N  U  L  L  N    6.5   .0045   37.0     —

AFFECTED
  Product  Versions                                    Fixed
  curl     7.7.0 –                                     —
  curl     a1d6ad26100bc493c7b04f1301b1634b7f5aa8b4 –  —
  curl     8.18.0 –                                    —

TIMELINE
  Mar 8   Reserved by curl
  Mar 11  Published (CNA: curl)
  Sep 15  EXPLOIT PUBLISHED — CVE-2026-3784 (curl). Public exploit reference added.

CWE-305 · CNA: curl · CVSS v3.1 · 5 references · NVD status: Modified

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.

Lifecycle

Complete event history — 3 events, chronological
Date	Event	Detail
March 8, 2026	Reserved	Reserved by curl
March 11, 2026	Published	Published (CNA: curl)
September 15, 2026	EXPLOIT PUBLISHED	EXPLOIT PUBLISHED — CVE-2026-3784 (curl). Public exploit reference added.

Affected

Affected products and packages — 3 rows
Vendor	Product / Package	Ecosystem	Version introduced	Fixed
curl	curl	—	7.7.0	—
curl	curl	—	a1d6ad26100bc493c7b04f1301b1634b7f5aa8b4	—
curl	curl	—	8.18.0	—

Weaknesses

CWE-305

References (5)

http://www.openwall.com/lists/oss-security/2026/03/11/3 [Mailing List, Third Party Advisory]
https://cert-portal.siemens.com/productcert/html/ssa-253495.html
https://curl.se/docs/CVE-2026-3784.html [Patch, Vendor Advisory]
https://curl.se/docs/CVE-2026-3784.json [Vendor Advisory]
https://hackerone.com/reports/3584903 [Exploit, Issue Tracking, Third Party Advisory]

Authoritative record: CVE-2026-3784 at cve.org

Vendors: curl

Weaknesses: CWE-305

About this page

This is a reference page, not a dated page of record. It assembles the complete lifecycle of CVE-2026-3784 from the CVE Program record, NVD enrichment, the CISA KEV catalog, EPSS, and OSV advisories. The box score's numbers (CVSS, EPSS, KEV status) are current as of Sunday, October 4, 2026 UTC and are re-derived as the archive grows; only dated daily editions are immutable pages of record. The authoritative source for this identifier is cve.org.