Medium severity5.9NVD Advisory· Published May 13, 2026· Updated May 14, 2026
CVE-2026-6253
CVE-2026-6253
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
Affected products
2Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
4- www.openwall.com/lists/oss-security/2026/04/29/11nvdMailing ListPatchThird Party Advisory
- curl.se/docs/CVE-2026-6253.htmlnvdPatchVendor Advisory
- hackerone.com/reports/3669637nvdExploitIssue TrackingThird Party Advisory
- curl.se/docs/CVE-2026-6253.jsonnvdVendor Advisory
News mentions
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