CVE-2026-82209

A flaw was found in libcurl when libpsl support is enabled. A remote attacker could exploit this vulnerability by setting a Set-Cookie header with a Domain attribute that explicitly matches a public suffix. This improper handling causes libcurl to save the cookie with a wildcard domain scope, leading to the cookie being inappropriately sent to arbitrary sibling subdomains under the same public suffix. This could result in sensitive information disclosure.

Red Hat rates this vulnerability as Low because the resulting impact is limited to cookie leakage to sibling subdomains under a suffix, not data modification or system compromise.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.

Mitigation for this issue is either not available or the currently available options do not meet the Red Hat Product Security criteria comprising ease of use and deployment, applicability to widespread installation base, or stability.