CVE•Published 2026-05-13•Modified 2026-05-14•0 articles on news•5 live references•NVD data

CVE-2026-6253Haxx · Curl

Vulnerability data via NVD (ingested)

CVSS v3.1

5.9

MEDIUM

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H

EPSS percentile

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Weaknesses (CWE)

CWE-522Insufficiently Protected Credentials

Description

curl might erroneously pass on credentials for a first proxy to a second proxy. This can happen when the following conditions are true: 1. curl is setup to use specific different proxies for different URL schemes 2. the first proxy needs credentials 3. the second proxy uses no credentials 4. while using the first proxy (using say `http://`), curl is asked to follow a redirect to a URL using another scheme (say `https://`), accessed using a second, different, proxy

Timeline

Published 2026-05-13

Modified 2026-05-14

External references

NVD MITRE Exploit-DB Sploitus VulnCheck

Search for exposed instances

Shodan + Censys queries derived from NVD's CPE data. The vuln tag catches assets Shodan has explicitly linked to this CVE; the product / banner fingerprints find exposed instances even when the vuln tag was never applied (which is common).

Shodan · vuln tag0 hosts

vuln:CVE-2026-6253

Hosts Shodan has explicitly fingerprinted as vulnerable.

Shodan · product

product:"Haxx Curl"

All exposed Haxx Curl instances — cross-reference with the CVE's affected-version range.

Shodan · banner/body mention

http.html:"Curl"

HTTP body or banner mentions "Curl" — catches deploys Shodan didn't identify as a product.

More intel sources (5)

Shodan report

vuln:CVE-2026-6253