CVE-2025-66506

A flaw was found in Fulcio, a free-to-use certificate authority. This vulnerability allows a denial of service (DoS) due to excessive memory allocation when processing a malicious OpenID Connect (OIDC) identity token containing numerous period characters.

This vulnerability is rated Important for Red Hat as Fulcio, a certificate authority used for issuing code signing certificates, is susceptible to a denial of service when processing a specially crafted OpenID Connect (OIDC) token. This could lead to resource exhaustion and service unavailability in affected Red Hat products that utilize Fulcio.

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.