CVE-2026-55893

UNKNOWN 0.0

Capstone SH disassembler `set_reg_n` heap buffer overflow via crafted SH2A FPU bytecode

CVSS Score

0.0

EPSS Score

0.0%

EPSS Percentile

0th

Capstone is a disassembly framework. In 6.0.0-Alpha9 and earlier, Capstone's arch/SH/SHDisassembler.c SH floating-point decoders such as opFADD, opFMUL, and opFSUB call set_reg() and set_reg_n() using sh_info.op.op_count without checking the fixed-size operands[] array. Repeated crafted instructions processed through cs_disasm_iter() or cs_disasm() with CS_ARCH_SH, CS_MODE_SH2A or CS_MODE_SH4A, CS_MODE_SHFPU, and CS_OPT_DETAIL can increment the operand count beyond the 176-byte sh_info allocation and perform a four-byte heap buffer overflow write. The corruption can crash the process and may enable code execution depending on heap layout. This issue is fixed in version 6.0.0-Alpha10.

CWE	CWE-122
Vendor	capstone-engine
Product	capstone
Published	Aug 20, 2026

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Affected Versions

capstone-engine / capstone

< 6.0.0-Alpha10

References

NVD ↗ CVE.org ↗ EPSS Data ↗

github.com: https://github.com/capstone-engine/capstone/security/advisories/GHSA-3hpv-wr3j-rxwh github.com: https://github.com/capstone-engine/capstone/pull/2968 github.com: https://github.com/capstone-engine/capstone/pull/2969 github.com: https://github.com/capstone-engine/capstone/commit/09e76802380b9e94d9720c44458d9d5282219e7e github.com: https://github.com/capstone-engine/capstone/commit/e17ee44a8307ea33375b4727ac4f987650bf7bed github.com: https://github.com/capstone-engine/capstone/releases/tag/6.0.0-Alpha10