CVE-2026-55893
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…
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.14%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 4.0
- 7.3 HIGHCVSS:4.0/AV:L/AC:H/AT:P/PR:N/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
- EPSS
- 0.14% probability · 4th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-122
- Source
- security-advisories@github.com
References
- https://github.com/capstone-engine/capstone/commit/09e76802380b9e94d9720c44458d9d5282219e7e
- https://github.com/capstone-engine/capstone/commit/e17ee44a8307ea33375b4727ac4f987650bf7bed
- https://github.com/capstone-engine/capstone/pull/2968
- https://github.com/capstone-engine/capstone/pull/2969
- https://github.com/capstone-engine/capstone/releases/tag/6.0.0-Alpha10
- https://github.com/capstone-engine/capstone/security/advisories/GHSA-3hpv-wr3j-rxwh
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.