High [CVE-2026-55893] Heap buffer overflow with potential code execution
This high-severity Red Hat Linux advisory covers CVE-2026-55893 affecting Red Hat Hardened Images, Red Hat Enterprise Linux 10, Red Hat Enterprise Linux 9.
Aggregated and source-linked by VulniPulse. Data sources, validation and limitations.
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Summary
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.
This vulnerability allows a local attacker to provide specially crafted SH2A FPU bytecode, leading to a heap buffer overflow. Red Hat severity: Moderate — CVSS 7 (CVSS:3.1/AV:L/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:H).
Weakness: CWE-805. Affected Red Hat products: Red Hat Hardened Images; Red Hat Enterprise Linux 10; Red Hat Enterprise Linux 9; Red Hat OpenShift Container Platform 4.
Red Hat fixing advisory: RHSA-2026:59419.
Affected products named by the advisory: Red Hat package: capstone.
Affected versions
No affected-version range was extracted from the source record. The vendor advisory is authoritative — check it before change work.
Official advisory · high-confidence parse· fetched 8 days ago·verify at source
- 6.0.0
- 6.0.0-Alpha10
- capstone-main-5.0.8-0.3.hum1
- RHSA-2026:59419
Official advisory · high-confidence parse· fetched 8 days ago·verify at source
Mitigation
Upgrade to a fixed release: 6.0.0, 6.0.0-Alpha10, capstone-main-5.0.8-0.3.hum1, RHSA-2026:59419. That is the remediation for this advisory.
The vendor advisory may list additional interim mitigations or workarounds not captured here — review it before change work.
Official advisory · high-confidence parse· fetched 8 days ago·verify at source
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