CVE-2026-58063
Description
A flaw was found in Bouncy Castle for Java. A remote attacker can exploit this vulnerability by providing a specially crafted BCFKS keystore file that specifies an unbounded Key Derivation Function (KDF) cost. This can lead to a Denial of Service (DoS) as the system attempts to process the file, consuming excessive resources and becoming unresponsive.
Statement
Bouncy Castle for Java is bundled as a cryptographic provider across numerous Red Hat products. Loading a BCFKS keystore honors an unbounded Key Derivation Function (KDF) cost from the untrusted file, so loading a crafted keystore forces excessive computation and a denial of service. Exploitation requires the application to load an attacker-supplied BCFKS keystore file. Note: Red Hat rates this Important (CVSS v3 7.5, A:H) versus the upstream CVEORG v4 score of 5.3 (Moderate, A:L).
Mitigation
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 bc-fips 1.0.2.7/2.0.2/2.1.3) once available for the affected product.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
The following CVSS metrics and score provided are preliminary and subject to review.
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.5 | 5.3 | N/A |
| Attack Vector | Network | Network | N/A |
| Attack Complexity | Low | Low | N/A |
| Privileges Required | None | None | N/A |
| User Interaction | None | None | N/A |
| Scope | Unchanged | Unchanged | N/A |
| Confidentiality | None | None | N/A |
| Integrity Impact | None | None | N/A |
| Availability Impact | High | Low | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
NVD: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L
Understanding the Weakness (CWE)
Availability
Technical Impact: DoS: Resource Consumption (CPU); DoS: Resource Consumption (Memory); DoS: Resource Consumption (Other)
When allocating resources without limits, an attacker could prevent other systems, applications, or processes from accessing the same type of resource. It can be easy for an attacker to consume many resources by rapidly making many requests or causing larger resources to be used than is needed.
Frequently Asked Questions
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