CriticalFix available
swupdate — security advisory
SWUpdate through 2026.05.1 contains an improper certificate validation vulnerability in crypto/swupdate_cms_verify_openssl.c that trusts untrusted X.509 certificates embedded in CMS SignedData for chain building. Attackers holding a signing key from a sibling intermediate under the same root can embed that intermediate in the signature to install malicious updates.
- Products
- swupdate
- Affected versions
- 2022.12+dfsg-4, 2022.12+dfsg-4+deb12u1, 2022.12+dfsg-4+deb12u1~bpo11+1, 2022.12+dfsg-4+deb12u2, 2024.12.1+dfsg-3, 2025.05+dfsg-1, 2025.05+dfsg-2, 2025.05+dfsg-2~bpo13+1, 2025.05+dfsg-3, 2025.05+dfsg-3~bpo13+1, 2025.12+dfsg-1, 2025.12+dfsg-10, 2025.12+dfsg-10~bpo13+1, 2025.12+dfsg-10~bpo13+2, 2025.12+dfsg-2, 2025.12+dfsg-2~bpo13+1, 2025.12+dfsg-3, 2025.12+dfsg-4, 2025.12+dfsg-5, 2025.12+dfsg-6, 2025.12+dfsg-7, 2025.12+dfsg-7~bpo13+1, 2025.12+dfsg-8, 2025.12+dfsg-9
- Fixed versions
- 2022.12+dfsg-4+deb12u3, 2026.05+dfsg-1
- CVEs
- CVE-2026-109399
- Confirmed fixed CVEs
- Not specified
- Updated in this feed
- 1 Nov 2026, 17:11 UTC · Revision 1
Source evidence
SWUpdate through 2026.05.1 contains an improper certificate validation vulnerability in crypto/swupdate_cms_verify_openssl.c that trusts untrusted X.509 certificates embedded in CMS SignedData for chain building. Attackers holding a signing key from a sibling intermediate under the same root can embed that intermediate in the signature to install malicious updates.
osv:DEBIAN-CVE-2026-109399
swupdate
Fixed versions: 2022.12+dfsg-4+deb12u3
swupdate
Fixed versions: 2026.05+dfsg-1
Complete source record
{
"id": "ad5d1af335ac0a4645fc3274bd37cf6ced63983c812c0a326145cefeb85c4b1f",
"url": "https://osv.dev/vulnerability/DEBIAN-CVE-2026-109399",
"method": "structured",
"payload": {
"kind": "advisory",
"title": "DEBIAN-CVE-2026-109399",
"summary": "SWUpdate through 2026.05.1 contains an improper certificate validation vulnerability in crypto/swupdate_cms_verify_openssl.c that trusts untrusted X.509 certificates embedded in CMS SignedData for chain building. Attackers holding a signing key from a sibling intermediate under the same root can embed that intermediate in the signature to install malicious updates.",
"evidence": "osv:DEBIAN-CVE-2026-109399",
"products": [
{
"name": {
"value": "swupdate",
"evidence": "/affected/0/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2022.12+dfsg-4+deb12u3",
"evidence": "/affected/0/ranges"
}
],
"affected_versions": [
{
"value": "2022.12+dfsg-4",
"evidence": "/affected/0/versions"
},
{
"value": "2022.12+dfsg-4+deb12u1",
"evidence": "/affected/0/versions"
},
{
"value": "2022.12+dfsg-4+deb12u1~bpo11+1",
"evidence": "/affected/0/versions"
},
{
"value": "2022.12+dfsg-4+deb12u2",
"evidence": "/affected/0/versions"
}
]
},
{
"name": {
"value": "swupdate",
"evidence": "/affected/1/package/name"
},
"prerequisites": [],
"fixed_versions": [
{
"value": "2026.05+dfsg-1",
"evidence": "/affected/1/ranges"
}
],
"affected_versions": [
{
"value": "2024.12.1+dfsg-3",
"evidence": "/affected/1/versions"
},
{
"value": "2025.05+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "2025.05+dfsg-2",
"evidence": "/affected/1/versions"
},
{
"value": "2025.05+dfsg-2~bpo13+1",
"evidence": "/affected/1/versions"
},
{
"value": "2025.05+dfsg-3",
"evidence": "/affected/1/versions"
},
{
"value": "2025.05+dfsg-3~bpo13+1",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-1",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-10",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-10~bpo13+1",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-10~bpo13+2",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-2",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-2~bpo13+1",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-3",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-4",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-5",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-6",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-7",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-7~bpo13+1",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-8",
"evidence": "/affected/1/versions"
},
{
"value": "2025.12+dfsg-9",
"evidence": "/affected/1/versions"
}
]
}
],
"severity": "critical",
"structured": {
"id": "DEBIAN-CVE-2026-109399",
"aliases": [
"DEBIAN-CVE-2026-109399"
],
"metrics": [
{
"type": "CVSS_V4",
"score": "CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/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"
},
{
"fixed": "2022.12+dfsg-4+deb12u3"
}
]
}
],
"package": {
"name": "swupdate",
"purl": "pkg:deb/debian/swupdate?arch=source&distro=bookworm",
"ecosystem": "Debian:12"
},
"versions": [
"2022.12+dfsg-4",
"2022.12+dfsg-4+deb12u1",
"2022.12+dfsg-4+deb12u1~bpo11+1",
"2022.12+dfsg-4+deb12u2"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-109399.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
},
{
"ranges": [
{
"type": "ECOSYSTEM",
"events": [
{
"introduced": "0"
},
{
"fixed": "2026.05+dfsg-1"
}
]
}
],
"package": {
"name": "swupdate",
"purl": "pkg:deb/debian/swupdate?arch=source&distro=forky",
"ecosystem": "Debian:14"
},
"versions": [
"2024.12.1+dfsg-3",
"2025.05+dfsg-1",
"2025.05+dfsg-2",
"2025.05+dfsg-2~bpo13+1",
"2025.05+dfsg-3",
"2025.05+dfsg-3~bpo13+1",
"2025.12+dfsg-1",
"2025.12+dfsg-10",
"2025.12+dfsg-10~bpo13+1",
"2025.12+dfsg-10~bpo13+2",
"2025.12+dfsg-2",
"2025.12+dfsg-2~bpo13+1",
"2025.12+dfsg-3",
"2025.12+dfsg-4",
"2025.12+dfsg-5",
"2025.12+dfsg-6",
"2025.12+dfsg-7",
"2025.12+dfsg-7~bpo13+1",
"2025.12+dfsg-8",
"2025.12+dfsg-9"
],
"database_specific": {
"source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-109399.json"
},
"ecosystem_specific": {
"urgency": "not yet assigned"
}
}
],
"modified": "2026-10-27T02:00:08.061735286Z",
"provider": "osv",
"upstream": [
"CVE-2026-109399"
],
"references": [
"https://security-tracker.debian.org/tracker/CVE-2026-109399"
]
},
"related_cves": [
{
"value": "CVE-2026-109399",
"evidence": "/upstream"
}
],
"security_relevant": true,
"severity_evidence": "/severity/0/score"
},
"source_id": "core-osv",
"document_id": 460006,
"published_at": "2026-10-12T16:17:05.557+00:00"
}