CVE-2026-59647

A flaw was found in Bouncy Castle for Java. The Certificate Request Message Format (CRMF) and Certificate Management Protocol (CMP) password-based Message Authentication Code (MAC) implementation allows for an unbounded iteration count. A remote attacker can exploit this by sending a specially crafted request, leading to a denial of service (DoS) due to excessive resource consumption.

Bouncy Castle for Java is bundled as a cryptographic provider across numerous Red Hat products. The CRMF/CMP password-based MAC honors an unbounded iteration count, so a crafted request forces excessive computation and a denial of service. Exploitation requires the application to process attacker-supplied CRMF/CMP messages. Note: Red Hat rates this Important (CVSS v3 7.5, A:H) versus the upstream CVEORG v4 score of 6.9 (Moderate, A:L).

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.

Red Hat is not aware of a mitigation for this flaw other than updating the affected Bouncy Castle component to a fixed version (bc-java 1.85, LTS 2.73.12, or BC-FJA bcpkix-fips 1.0.12/2.0.12/2.1.12) once available for the affected product.