CVE-2026-55894
Capstone SH disassembler `sh_disassemble` out-of-bounds read via crafted SH2A bytecode
- State
- Published
- Severity
- 6.8 Medium
- Published
- Aug 20, 2026
- Updated
- Aug 21, 2026
- Reserved
- Jun 17, 2026
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.
Scores
| CVSS | Score | Vector | Source |
|---|---|---|---|
| 4.0 | 6.8 Medium | CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N | GitHub_M |
Weaknesses
- CWE-125 Out-of-bounds Read
Affected Products
| Product | Versions |
|---|---|
capstonecapstone-engine |
|
References
- https://github.com/capstone-engine/capstone/security/advisories/GHSA-gf2c-xwcp-hvf4
- https://github.com/capstone-engine/capstone/pull/2968
- https://github.com/capstone-engine/capstone/pull/2969
- https://github.com/capstone-engine/capstone/commit/09e76802380b9e94d9720c44458d9d5282219e7e
- https://github.com/capstone-engine/capstone/commit/e17ee44a8307ea33375b4727ac4f987650bf7bed
- https://github.com/capstone-engine/capstone/releases/tag/6.0.0-Alpha10
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