MediumFix available
shim — security advisory
An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information. This issue may expose sensitive data during the system's boot phase.
- Products
- shim
- Affected versions
- 15.7-1, 15.8-1~deb10u1, 15.8-1~deb11u1
- Fixed versions
- 15.8-1, 15.8-1~deb12u1
- CVEs
- CVE-2023-40550
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 15:57 UTC · Revision 1
Source evidence
An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information. This issue may expose sensitive data during the system's boot phase.
osv:DEBIAN-CVE-2023-40550
shim
Fixed versions: 15.8-1~deb12u1
shim
Fixed versions: 15.8-1
shim
Fixed versions: 15.8-1
Complete source record
{
"id": "207c9a583d2802cb32c07b1e64122f8c058b28fae4cedacc68107265a02ad041",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2023-40550",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2023-40550",
"summary": "An out-of-bounds read flaw was found in Shim when it tried to validate the SBAT information. This issue may expose sensitive data during the system's boot phase.",
"evidence": "osv:DEBIAN-CVE-2023-40550",
"products": [
{
"name": {
"value": "shim",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "15.8-1~deb12u1",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "15.7-1",
"evidence": "/affected/0/versions"
},
{
"value": "15.8-1~deb10u1",
"evidence": "/affected/0/versions"
},
{
"value": "15.8-1~deb11u1",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "shim",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "15.8-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": []
},
{
"name": {
"value": "shim",
"evidence": "/affected/2/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "15.8-1",
"evidence": "/affected/2/ranges"
}
],
"affected_versions": []
}
],
"severity": "medium",
"structured": {
"id": "DEBIAN-CVE-2023-40550",
"aliases": [
"DEBIAN-CVE-2023-40550"
],
"metrics": [
{
"type": "CVSS_V3",
"score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N"
}
],
"affected": [
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "15.8-1~deb12u1"
}
]
}
],
"package": {
"name": "shim",
"purl": "pkg:deb/debian/shim?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"15.7-1",
"15.8-1~deb10u1",
"15.8-1~deb11u1"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-40550.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "15.8-1"
}
]
}
],
"package": {
"name": "shim",
"purl": "pkg:deb/debian/shim?arch=source&distro=trixie",
"ecosystem": "Debian:13"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-40550.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "15.8-1"
}
]
}
],
"package": {
"name": "shim",
"purl": "pkg:deb/debian/shim?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2023-40550.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-26T18:02:31.603869039Z",
"provider": "osv",
"upstream": [
"CVE-2023-40550"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2023-40550"
]
},
"related_cves": [
{
"value": "CVE-2023-40550",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 456176,
"published_at": "2024-01-29T17:15:08.773+00:00"
}