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National Vulnerability Database

National Vulnerability Database

NVD

National Vulnerability Database
  1. Vulnerabilities

CVE-2026-6253 Detail

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


Metrics

 
NVD enrichment efforts reference publicly available information to associate vector strings. CVSS information contributed by other sources is also displayed.
CVSS 4.0 Severity and Vector Strings:

NIST CVSS score
NIST: NVD
N/A
NVD assessment not yet provided.

References to Advisories, Solutions, and Tools

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URL Source(s) Tag(s)
http://www.openwall.com/lists/oss-security/2026/04/29/11 CVE Mailing List  Patch  Third Party Advisory 
https://curl.se/docs/CVE-2026-6253.html curl Patch  Vendor Advisory 
https://curl.se/docs/CVE-2026-6253.json curl Vendor Advisory 
https://hackerone.com/reports/3669637 CISA-ADP, curl Exploit  Issue Tracking  Third Party Advisory 

Weakness Enumeration

CWE-ID CWE Name Source
CWE-522 Insufficiently Protected Credentials cwe source acceptance level NIST  

Known Affected Software Configurations Switch to CPE 2.2

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Change History

4 change records found show changes

Quick Info

CVE Dictionary Entry:
CVE-2026-6253
NVD Published Date:
05/13/2026
NVD Last Modified:
05/14/2026
Source:
curl