UBUNTU-CVE-2026-109399

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Source
https://ubuntu.com/security/CVE-2026-109399
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-109399.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-109399
Upstream
Published
2026-10-12T16:17:00Z
Modified
2026-10-17T12:59:49Z
Severity
  • 8.1 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • 9.2 (Critical) CVSS_V4 - 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 CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

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.

References

Affected packages

Ubuntu:22.04:LTS / swupdate

Package

Name
swupdate
Purl
pkg:deb/ubuntu/swupdate?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2020.*
2020.11-2
2021.*
2021.04-1.1
2021.04-2
2021.04-2build1
2021.11-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libswupdate0.1",
            "binary_version":  "2021.11-1"
        },
        {
            "binary_name":  "lua-swupdate",
            "binary_version":  "2021.11-1"
        },
        {
            "binary_name":  "swupdate",
            "binary_version":  "2021.11-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-109399.json"

Ubuntu:24.04:LTS / swupdate

Package

Name
swupdate
Purl
pkg:deb/ubuntu/swupdate?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2023.*
2023.05+dfsg-3
2023.05+dfsg-4
2023.05+dfsg-4build1
2023.05+dfsg-5
2023.12+dfsg-1
2023.12.1+dfsg-1ubuntu1
2023.12.1+dfsg-1ubuntu4
2023.12.1+dfsg-1ubuntu5

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libswupdate0.1",
            "binary_version":  "2023.12.1+dfsg-1ubuntu5"
        },
        {
            "binary_name":  "lua-swupdate",
            "binary_version":  "2023.12.1+dfsg-1ubuntu5"
        },
        {
            "binary_name":  "swupdate",
            "binary_version":  "2023.12.1+dfsg-1ubuntu5"
        },
        {
            "binary_name":  "swupdate-www",
            "binary_version":  "2023.12.1+dfsg-1ubuntu5"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-109399.json"

Ubuntu:26.10 / swupdate

Package

Name
swupdate
Purl
pkg:deb/ubuntu/swupdate?arch=source&distro=stonking

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2025.*
2025.12+dfsg-4ubuntu1
2026.*
2026.05+dfsg-3ubuntu2
2026.05+dfsg-4ubuntu1
2026.05.1+dfsg-1ubuntu1
2026.05.1+git20261001+dfsg-1ubuntu1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libswupdate0.1",
            "binary_version":  "2026.05.1+git20261001+dfsg-1ubuntu1"
        },
        {
            "binary_name":  "lua-swupdate",
            "binary_version":  "2026.05.1+git20261001+dfsg-1ubuntu1"
        },
        {
            "binary_name":  "swupdate",
            "binary_version":  "2026.05.1+git20261001+dfsg-1ubuntu1"
        },
        {
            "binary_name":  "swupdate-www",
            "binary_version":  "2026.05.1+git20261001+dfsg-1ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-109399.json"

Ubuntu:26.04:LTS / swupdate

Package

Name
swupdate
Purl
pkg:deb/ubuntu/swupdate?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected

Affected versions

2025.*
2025.05+dfsg-2ubuntu1
2025.05+dfsg-3ubuntu1
2025.12+dfsg-1ubuntu1
2025.12+dfsg-2ubuntu1
2025.12+dfsg-3ubuntu1
2025.12+dfsg-4ubuntu1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "libswupdate0.1",
            "binary_version":  "2025.12+dfsg-4ubuntu1"
        },
        {
            "binary_name":  "lua-swupdate",
            "binary_version":  "2025.12+dfsg-4ubuntu1"
        },
        {
            "binary_name":  "swupdate",
            "binary_version":  "2025.12+dfsg-4ubuntu1"
        },
        {
            "binary_name":  "swupdate-www",
            "binary_version":  "2025.12+dfsg-4ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-109399.json"