capstone — security advisory
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.
- Products
- capstone
- Affected versions
- 4.0.2-5, 4.0.2-5.1, 5.0-1~exp1, 5.0.1-1~exp1, 5.0.3-1, 5.0.5-1, 5.0.6-1, 5.0.7-1, 5.0.7-1~deb13u1, 5.0.7-2, 5.0.9-1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-55893
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 22:57 UTC · Revision 1
Source evidence
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.
osv:DEBIAN-CVE-2026-55893
capstone
Fixed versions: Not specified
capstone
Fixed versions: Not specified
capstone
Fixed versions: Not specified
Complete source record
{
"id": "aa4c9f0807b70839fea20f169679b4868a889c6dd96e1b9ffde53d7ee2efdda1",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-55893",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-55893",
"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.",
"evidence": "osv:DEBIAN-CVE-2026-55893",
"products": [
{
"name": {
"value": "capstone",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "4.0.2-5",
"evidence": "/affected/0/versions"
},
{
"value": "4.0.2-5.1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0-1~exp1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.1-1~exp1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.3-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.5-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.6-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.7-1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.7-1~deb13u1",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.7-2",
"evidence": "/affected/0/versions"
},
{
"value": "5.0.9-1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "capstone",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.0.6-1",
"evidence": "/affected/1/versions"
},
{
"value": "5.0.7-1",
"evidence": "/affected/1/versions"
},
{
"value": "5.0.7-1~deb13u1",
"evidence": "/affected/1/versions"
},
{
"value": "5.0.7-2",
"evidence": "/affected/1/versions"
},
{
"value": "5.0.9-1",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "capstone",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "5.0.6-1",
"evidence": "/affected/2/versions"
},
{
"value": "5.0.7-1",
"evidence": "/affected/2/versions"
},
{
"value": "5.0.7-1~deb13u1",
"evidence": "/affected/2/versions"
},
{
"value": "5.0.7-2",
"evidence": "/affected/2/versions"
},
{
"value": "5.0.9-1",
"evidence": "/affected/2/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "DEBIAN-CVE-2026-55893",
"aliases": [
"DEBIAN-CVE-2026-55893"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "capstone",
"purl": "pkg:deb/debian/capstone?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"4.0.2-5",
"4.0.2-5.1",
"5.0-1~exp1",
"5.0.1-1~exp1",
"5.0.3-1",
"5.0.5-1",
"5.0.6-1",
"5.0.7-1",
"5.0.7-1~deb13u1",
"5.0.7-2",
"5.0.9-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55893.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "capstone",
"purl": "pkg:deb/debian/capstone?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"versions": [
"5.0.6-1",
"5.0.7-1",
"5.0.7-1~deb13u1",
"5.0.7-2",
"5.0.9-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55893.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "capstone",
"purl": "pkg:deb/debian/capstone?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"5.0.6-1",
"5.0.7-1",
"5.0.7-1~deb13u1",
"5.0.7-2",
"5.0.9-1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-55893.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-23T17:47:30.405293526Z",
"provider": "osv",
"upstream": [
"CVE-2026-55893"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-55893"
]
},
"related_cves": [
{
"value": "CVE-2026-55893",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 417309,
"published_at": "2026-08-20T22:17:22.787+00:00"
}