CVE-2026-59643
Description
A flaw was found in Bouncy Castle for Java and Bouncy Castle for Java FIPS (BC-FJA). This vulnerability allows an attacker to bypass OpenPGP inline-signature policy failures, which are silently ignored by the software. This silent disregard of policy failures can lead to a compromise of data integrity, as users may mistakenly believe that signature policies are being enforced when they are not. This could result in the acceptance of maliciously altered or unauthorized data.
Statement
This flaw has an Important impact. Bouncy Castle for Java's OpenPGP (bcpg) module silently ignores inline-signature policy failures instead of reporting them to the application. When an application processes OpenPGP-signed data with signature policy constraints, policy violations are not enforced or reported. A remote attacker can exploit this by sending OpenPGP-signed data that violates signature policies. The application will process the data as if the signature policy was satisfied, leading to acceptance of maliciously altered or unauthorized data. This affects applications using Bouncy Castle's bcpg module for OpenPGP signature verification with policy enforcement.
Mitigation
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.
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 | 7.5 | 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 | High | High | N/A |
| Availability Impact | None | None | N/A |
Vector
Red Hat: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
NVD: 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: Varies by Context; Unexpected State; Alter Execution Logic
An attacker could utilize an ignored error condition to place the system in an unexpected state that could lead to the execution of unintended logic and could cause other unintended behavior.
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