CVE-2026-55894
Description
A flaw was found in Capstone, a disassembly framework. The sh_disassemble() function incorrectly processes 16-bit instructions, leading to an attempt to read data from an unauthorized memory location (an out-of-bounds read). A remote attacker could exploit this by providing specially crafted bytecode to an application using Capstone in specific modes (SH2A or SH4A with SHFPU). This could cause the application to crash, resulting in a Denial of Service (DoS), where the service becomes unavailable. No code execution or information disclosure was demonstrated as a result of this flaw.
Statement
This Moderate impact flaw in Capstone's SH disassembler can lead to a denial of service. An application processing specially crafted SH2A or SH4A bytecode with Capstone configured for these specific modes may crash due to an out-of-bounds read. This issue does not result in code execution or information disclosure, limiting its severity to service disruption.
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).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 5.5 | N/A | N/A |
| Attack Vector | Local | N/A | N/A |
| Attack Complexity | Low | N/A | N/A |
| Privileges Required | None | N/A | N/A |
| User Interaction | Required | N/A | N/A |
| Scope | Unchanged | N/A | N/A |
| Confidentiality | None | N/A | N/A |
| Integrity Impact | None | N/A | N/A |
| Availability Impact | High | N/A | N/A |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
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