CVE-2026-6253

None

No severity ratings or metrics are available. When they are, we'll update the corresponding info on the page.

curl might erroneously pass on credentials for a first proxy to a second proxy.

This can happen when the following conditions are true:

curl is setup to use specific different proxies for different URL schemes
the first proxy needs credentials
the second proxy uses no credentials
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

Insufficiently Protected Credentials

Found an issue in the description? Have something to add? Feel free to write us 👾

Weakness Enumeration

CVE-2026-6253

Curl