CVE-2026-6253

CVE-2026-6253 concerns curl leaking credentials from the first proxy when a redirect-to a second proxy occurs. The issue arises under multi-proxy configurations where the first proxy requires credentials, the second proxy does not, and a redirect from an http URL to an https URL uses the second p...

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

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. whil...