CVE-2026-6253
MEDIUM EPSS 46.0%
Published May 13, 20261mo ago · Modified Jun 17, 20261w ago
5.9 CVSS 3.1
Published May 13, 2026 1mo ago
Last Modified Jun 17, 2026 1w ago
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
CVSS Details
Base Score
Exploitability
Impact
Vector string
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H Attack Vector Network
Attack Complexity High
Privileges Required None
User Interaction None
Scope Unchanged
Confidentiality None
Integrity None
Availability High
Threat Intelligence
EPSS Exploit Probability
46.0% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available
Weaknesses 1
CWE-522
Affected Products 1
| Vendor | Product | Version | Range |
|---|---|---|---|
| haxx | curl | * | ≥7.14.1 – <8.20.0 |
References 4
- openwall.com http://www.openwall.com/lists/oss-security/2026/04/29/11
- curl.se https://curl.se/docs/CVE-2026-6253.html
- curl.se https://curl.se/docs/CVE-2026-6253.json
- hackerone.com https://hackerone.com/reports/3669637
Remediation
- openwall.com http://www.openwall.com/lists/oss-security/2026/04/29/11
- curl.se https://curl.se/docs/CVE-2026-6253.html