CVE-2026-59642
Description
A flaw was found in Bouncy Castle for Java. This vulnerability allows a remote attacker to bypass cryptographic integrity checks in the Cryptographic Message Syntax (CMS) AuthenticatedData content without requiring user interaction or elevated privileges. Specifically, when authentication attributes (authAttrs) are present, the content is not properly bound to the Message Authentication Code (MAC). This could lead to a high impact on data integrity, where an attacker might be able to alter authenticated data without detection.
Statement
Bouncy Castle for Java is bundled as a cryptographic provider by numerous Red Hat products. When CMS AuthenticatedData is processed with authentication attributes (authAttrs) present, the content is not cryptographically bound to the MAC, allowing an attacker to alter authenticated data without detection. Exploitation requires an application to process attacker-controlled CMS AuthenticatedData using the affected Bouncy Castle APIs. Affected Red Hat products consume Bouncy Castle transitively (e.g. resteasy, ceph, Keycloak/RHSSO, EAP) and are addressed via the delegated component trackers.
Mitigation
Red Hat is not aware of a mitigation for this flaw other than updating the affected Bouncy Castle component (bc-java 1.85, LTS 2.73.12, or BC-FJA 1.0.12/2.0.12/2.1.12) once available.
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 | N/A | N/A |
| Attack Vector | Network | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | None | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | High | N/A | N/A |
| Availability Impact | None | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
Understanding the Weakness (CWE)
Integrity,Other
Technical Impact: Modify Application Data; Other
Integrity checks usually use a secret key that helps authenticate the data origin. Skipping integrity checking generally opens up the possibility that new data from an invalid source can be injected.
Integrity,Other
Technical Impact: Other
Data that is parsed and used may be corrupted.
Non-Repudiation,Other
Technical Impact: Hide Activities; Other
Without a checksum check, it is impossible to determine if any changes have been made to the data after it was sent.
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