Medium [CVE-2026-49282] Denial of service via out-of-bounds read in M68K and RISCV backends

Capstone is a disassembly framework. Prior to version 6.0.0-Alpha9, Capstone's public `cs_insn_name()` API forwards caller-supplied instruction IDs directly to the selected architecture backend.

Most backends validate the ID before indexing instruction-name tables, but the M68K and RISCV backends have missing or incomplete bounds checks. On a Capstone handle opened for M68K or RISCV, a caller-controlled invalid instruction ID can trigger an out-of-bounds read and crash the process.

The demonstrated impact is availability loss in applications or bindings that expose instruction-name lookup to untrusted IDs. No code execution or data disclosure was demonstrated.

A flaw was found in Capstone. The `cs_insn_name()` application programming interface (API) in the M68K and RISCV backends does not properly validate caller-supplied instruction IDs.

Moderate: This flaw in Capstone's M68K and RISCV backends can lead to a denial of service. Applications that utilize Capstone and expose the `cs_insn_name()` API to untrusted instruction IDs without proper validation are susceptible to an out-of-bounds read, resulting in a crash.

The impact is limited to availability and does not involve code execution or information disclosure. Red Hat severity: Moderate — CVSS 6.2 (CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H).

Weakness: CWE-125.