CVE-2026-6276

HIGH7.5

stale custom cookie host causes cookie leak

Published May 13, 2026

Modified 3 days ago

Details

Using libcurl, when a custom Host: header is first set for an HTTP request and a second request is subsequently done using the same easy handle but without the custom Host: header set, the second request would use stale information and pass on cookies meant for the first host in the second request. Leak them.

References

WEB

http://www.openwall.com/lists/oss-security/2026/04/29/13

WEB

https://curl.se/docs/CVE-2026-6276.html

WEB

https://curl.se/docs/CVE-2026-6276.json

DETECTION

https://hackerone.com/reports/3671818

ADVISORY

https://www.cve.org/CVERecord?id=CVE-2026-6276

CVSS Analysis