High
ocaml-cstruct — security advisory
The cstruct package before 6.3.0 for OCaml mishandles indexes.
- Products
- ocaml-cstruct
- Affected versions
- 6.0.0-1build1, 6.0.1-1build1, 6.0.1-1build3, 6.2.0-2build1, 6.2.0-2build2, 6.2.0-2build3, 6.2.0-3build10, 6.2.0-3build11, 6.2.0-3build13, 6.2.0-3build9, 6.2.0-4build1
- Fixed versions
- Not specified
- CVEs
- CVE-2026-89087
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 31 Oct 2026, 03:30 UTC · Revision 1
Source evidence
The cstruct package before 6.3.0 for OCaml mishandles indexes.
osv:UBUNTU-CVE-2026-89087
ocaml-cstruct
Fixed versions: Not specified
ocaml-cstruct
Fixed versions: Not specified
ocaml-cstruct
Fixed versions: Not specified
ocaml-cstruct
Fixed versions: Not specified
Complete source record
{
"id": "c90240ac06526c79778a068c7f43c94035a97c2560349ff2ab860c1a5cda7ee7",
"url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-89087",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "UBUNTU-CVE-2026-89087",
"summary": "The cstruct package before 6.3.0 for OCaml mishandles indexes.",
"evidence": "osv:UBUNTU-CVE-2026-89087",
"products": [
{
"name": {
"value": "ocaml-cstruct",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.0.0-1build1",
"evidence": "/affected/0/versions"
},
{
"value": "6.0.1-1build1",
"evidence": "/affected/0/versions"
},
{
"value": "6.0.1-1build3",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "ocaml-cstruct",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
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"affected_versions": [
{
"value": "6.2.0-2build1",
"evidence": "/affected/1/versions"
},
{
"value": "6.2.0-2build2",
"evidence": "/affected/1/versions"
},
{
"value": "6.2.0-2build3",
"evidence": "/affected/1/versions"
}
]
},
{
"name": {
"value": "ocaml-cstruct",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.2.0-3build13",
"evidence": "/affected/2/versions"
},
{
"value": "6.2.0-4build1",
"evidence": "/affected/2/versions"
}
]
},
{
"name": {
"value": "ocaml-cstruct",
"evidence": "/affected/3/package/name"
},
"prerequisites": [],
"fixed_versions": [],
"affected_versions": [
{
"value": "6.2.0-3build9",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.0-3build10",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.0-3build11",
"evidence": "/affected/3/versions"
},
{
"value": "6.2.0-3build13",
"evidence": "/affected/3/versions"
}
]
}
],
"severity": "high",
"structured": {
"id": "UBUNTU-CVE-2026-89087",
"aliases": [
"UBUNTU-CVE-2026-89087"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:L"
},
{
"type": "Ubuntu",
"score": "medium"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
]
}
],
"package": {
"name": "ocaml-cstruct",
"purl": "pkg:deb/ubuntu/ocaml-cstruct?arch=source&distro=jammy",
"ecosystem": "Ubuntu:22.04:LTS"
},
"versions": [
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"6.0.1-1build1",
"6.0.1-1build3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-89087.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcstruct-ocaml",
"binary_version": "6.0.1-1build3"
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]
}
},
{
"ranges": [
{
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"events": [
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}
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}
],
"package": {
"name": "ocaml-cstruct",
"purl": "pkg:deb/ubuntu/ocaml-cstruct?arch=source&distro=noble",
"ecosystem": "Ubuntu:24.04:LTS"
},
"versions": [
"6.2.0-2build1",
"6.2.0-2build2",
"6.2.0-2build3"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-89087.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcstruct-ocaml",
"binary_version": "6.2.0-2build3"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
}
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}
],
"package": {
"name": "ocaml-cstruct",
"purl": "pkg:deb/ubuntu/ocaml-cstruct?arch=source&distro=stonking",
"ecosystem": "Ubuntu:26.10"
},
"versions": [
"6.2.0-3build13",
"6.2.0-4build1"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-89087.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcstruct-ocaml",
"binary_version": "6.2.0-4build1"
}
]
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
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}
]
}
],
"package": {
"name": "ocaml-cstruct",
"purl": "pkg:deb/ubuntu/ocaml-cstruct?arch=source&distro=resolute",
"ecosystem": "Ubuntu:26.04:LTS"
},
"versions": [
"6.2.0-3build9",
"6.2.0-3build10",
"6.2.0-3build11",
"6.2.0-3build13"
],
"database_specific": {
"source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-89087.json"
},
"ecosystem_specific": {
"binaries": [
{
"binary_name": "libcstruct-ocaml",
"binary_version": "6.2.0-3build13"
}
]
}
}
],
"modified": "2026-10-17T13:01:16.259434303Z",
"provider": "osv",
"upstream": [
"CVE-2026-89087"
],
"references": [
"https://ubuntu.com/security/CVE-2026-89087",
"https://www.cve.org/CVERecord?id=CVE-2026-89087",
"https://osv.dev/vulnerability/OSEC-2026-20",
"https://github.com/mirage/ocaml-cstruct/pull/324"
]
},
"related_cves": [
{
"value": "CVE-2026-89087",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 361441,
"published_at": "2026-09-10T20:17:00+00:00"
}