CVE-2026-55894

Capstone SH disassembler `sh_disassemble` out-of-bounds read via crafted SH2A bytecode

MEDIUM
6.8
CVSS Score
Published: August 20, 2026 at 09:31 PM UTC
Updated: October 18, 2026 at 08:10 PM UTC
1 product affected across 1 vendorCapstone

Using capstone by capstone-engine?

Get instant alerts when new vulnerabilities affect capstone - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
MEDIUM6.8
Exploit prediction
EPSS 0.2%
SSVC
PoC

Description

Capstone is a disassembly framework. In 6.0.0-Alpha9 and earlier, Capstone's arch/SH/SHDisassembler.c sh_disassemble() function computes an idx value from a raw 16-bit instruction without ensuring it is within the active mode-specific decode[] function-pointer table. An application using CS_ARCH_SH with CS_MODE_SH2A or CS_MODE_SH4A and CS_MODE_SHFPU can pass crafted bytecode through cs_disasm_iter() or cs_disasm(), causing the decode[idx] test to read outside the table and terminate the process with a segmentation fault. No code execution or information disclosure was demonstrated. This issue is fixed in version 6.0.0-Alpha10.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 6.0.0-Alpha10
Affected range stops below 6.0.0-Alpha10, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatablePartial impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

6.8MEDIUMGitHub_M
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-125

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card