0.0
NA
CVE-2026-6253
proxy credentials leak over redirect-to proxy
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

INFO

Published Date :

May 13, 2026, 8:28 a.m.

Last Modified :

May 13, 2026, 9:05 a.m.

Remotely Exploit :

No

Source :

curl
Affected Products

The following products are affected by CVE-2026-6253 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Haxx curl
Solution
Update curl to prevent proxy credential leakage between different URL schemes.
  • Update curl to the latest version.
  • Configure proxy settings carefully.
  • Avoid using different proxies for different schemes.
  • Test proxy behavior with redirects.

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2026-6253 vulnerability anywhere in the article.

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.