CVE-2026-3784: wrong proxy connection reuse with credentials
Advisory generated from the CVE record, CISA, Exploit Observer and VEDAS: what it is, whether it is exploited, who is affected, and how to fix and detect it.
Generated by VEDAS. Scores as of 2026-11-04 15:41 UTC. Rebuilt every few hours from cve-scores, CISA KEV and vedas-signatures. How this works and its limits.
What it is
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.
Description quoted from the CVE record (assigned by curl, published 2026-03-11).
Weakness: Authentication Bypass by Primary Weakness; CWE-305 Authentication Bypass by Primary Weakness
How it can be exploited
Exploitable over the network with low attack complexity needing no privileges and no user interaction. Impact: confidentiality low, integrity low, availability none. CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N
CISA assessment (SSVC): CISA has no evidence of exploitation. Automatable: yes. Technical impact: partial.
Public exploit evidence (Exploit Observer)
Exploit Observer found 2 research write-ups naming this CVE.
See all 15 references on Exploit Observer
Live scores
- EPSS
- 0.004
low predicted chance of attack - VEDAS
- 0.838
likely exploited - On CISA KEV
- Not listed
- Detection rule
- No public rule yet
Who is affected
| Product | Affected | Not affected |
|---|---|---|
| curl | from 7.7.0 before 8.14.2 from 8.15.0 before 8.16.1 from 8.17.0 before 8.19.0 | Not stated |
| curl | from a1d6ad26100b before 5f13a7645e56 (git commit) | Not stated |
| curl | version 8.18.0 version 8.17.0 version 8.16.0 version 8.15.0 version 8.14.1 version 8.14.0 version 8.13.0 version 8.12.1 and 183 more ranges | Not stated |
Version ranges exactly as the CVE record states them. “Before X” means X is the first fixed version.
How to fix it
Fixed versions stated in the CVE record: 8.14.2, 8.16.1, 8.19.0.
How to detect it
There is no open VEDAS detection rule for this bug yet. It is listed on the detection gaps page if CISA has confirmed attacks.
References
Other references
- https://curl.se/docs/CVE-2026-3784.json
- https://curl.se/docs/CVE-2026-3784.html
- https://hackerone.com/reports/3584903
- http://www.openwall.com/lists/oss-security/2026/03/11/3
- https://cert-portal.siemens.com/productcert/html/ssa-253495.html
Other databases
Where this comes from
This advisory is generated automatically by VEDAS from: CVE.org record, cve-scores (EPSS and VEDAS), Exploit Observer. Text in quotes is reproduced from the source; everything else is a fixed template filled with source fields. Nothing here is written by a language model. Check the vendor advisory before acting, and read how VEDAS and Exploit Observer work, and their limits.
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