UBUNTU-CVE-2026-97876

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Source
https://ubuntu.com/security/CVE-2026-97876
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-97876
Upstream
Published
2026-10-02T11:17:00Z
Modified
2026-10-08T09:53:35Z
Severity
  • 6.4 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:H/PR:H/UI:N/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A local attacker with control over GRUB's configuration can bypass lockdown restrictions when booting with Secure Boot and load an unsigned GRUB module, while GRUB continues to report lockdown is enabled. The vulnerability is caused by insufficient validation of the MMIO base address passed to the GRUB serial command. GRUB does not validate that the base address corresponds to a UART device, rather than being an arbitrary memory address. This allows an attacker to trick GRUB into writing non-arbitrary data at an attacker-controlled address, including resetting the grub_file_verifiers list in a way that disables the subsequent verification of loaded modules.

References

Affected packages

Ubuntu:16.04:LTS
grub2-signed

Package

Name
grub2-signed
Purl
pkg:deb/ubuntu/grub2-signed?arch=source&distro=xenial

Affected ranges

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

Affected versions

1.*
1.55
1.56
1.57
1.58
1.59
1.61
1.62
1.63
1.64
1.65
1.66
1.66.1
1.66.2
1.66.6
1.66.7
1.66.8
1.66.9
1.66.11
1.66.12
1.66.14
1.66.15
1.66.16
1.66.17
1.66.18
1.66.19
1.66.20
1.66.21
1.66.22
1.66.23
1.66.26
1.66.27
1.66.28
1.66.29
1.167~16.04.1
1.167~16.04.2
1.167~16.04.4
1.167~16.04.6

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.167~16.04.6+2.04-1ubuntu44.1.2"
        },
        {
            "binary_name": "grub-efi-arm64-signed",
            "binary_version": "1.167~16.04.6+2.04-1ubuntu44.1.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
grub2-unsigned

Package

Name
grub2-unsigned
Purl
pkg:deb/ubuntu/grub2-unsigned?arch=source&distro=xenial

Affected ranges

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

Affected versions

2.*
2.04-1ubuntu44
2.04-1ubuntu44.1
2.04-1ubuntu44.1.2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.04-1ubuntu44.1.2"
        },
        {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.04-1ubuntu44.1.2"
        },
        {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.04-1ubuntu44.1.2"
        },
        {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.04-1ubuntu44.1.2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
Ubuntu:18.04:LTS
grub2-signed

Package

Name
grub2-signed
Purl
pkg:deb/ubuntu/grub2-signed?arch=source&distro=bionic

Affected ranges

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

Affected versions

1.*
1.85
1.86
1.87
1.89
1.91
1.92
1.93
1.93.1
1.93.2
1.93.3
1.93.4
1.93.5
1.93.7
1.93.8
1.93.10
1.93.11
1.93.13
1.93.14
1.93.15
1.93.16
1.93.18
1.93.19
1.93.20
1.93.21
1.93.22
1.93.24
1.167~18.04.1
1.167~18.04.3
1.167~18.04.5
1.173.2~18.04.1
1.187.2~18.04.1
1.187.3~18.04.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.187.3~18.04.1+2.06-2ubuntu14.1"
        },
        {
            "binary_name": "grub-efi-arm64-signed",
            "binary_version": "1.187.3~18.04.1+2.06-2ubuntu14.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
grub2-unsigned

Package

Name
grub2-unsigned
Purl
pkg:deb/ubuntu/grub2-unsigned?arch=source&distro=bionic

Affected ranges

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

Affected versions

2.*
2.04-1ubuntu44
2.04-1ubuntu44.1
2.04-1ubuntu44.1.2
2.04-1ubuntu47.4
2.06-2ubuntu14
2.06-2ubuntu14.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.06-2ubuntu14.1"
        },
        {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.06-2ubuntu14.1"
        },
        {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.06-2ubuntu14.1"
        },
        {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.06-2ubuntu14.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
Ubuntu:20.04:LTS
grub2-signed

Package

Name
grub2-signed
Purl
pkg:deb/ubuntu/grub2-signed?arch=source&distro=focal

Affected ranges

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

Affected versions

1.*
1.128
1.129
1.130
1.131
1.133
1.134
1.135
1.136
1.137
1.138
1.139
1.140
1.141
1.142
1.142.1
1.142.3
1.142.4
1.142.5
1.142.6
1.142.8
1.142.9
1.142.10
1.142.11
1.167
1.167.2
1.173.2~20.04.1
1.173.4
1.187.2~20.04.2
1.187.3~20.04.1
1.187.4~20.04.1
1.187.6~20.04.1
1.187.12~20.04

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.187.12~20.04+2.06-2ubuntu14.8"
        },
        {
            "binary_name": "grub-efi-arm64-signed",
            "binary_version": "1.187.12~20.04+2.06-2ubuntu14.8"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
grub2-unsigned

Package

Name
grub2-unsigned
Purl
pkg:deb/ubuntu/grub2-unsigned?arch=source&distro=focal

Affected ranges

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

Affected versions

2.*
2.04-1ubuntu44
2.04-1ubuntu44.2
2.04-1ubuntu47.4
2.04-1ubuntu47.5
2.06-2ubuntu14
2.06-2ubuntu14.1
2.06-2ubuntu14.2
2.06-2ubuntu14.4
2.06-2ubuntu14.8

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.06-2ubuntu14.8"
        },
        {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.06-2ubuntu14.8"
        },
        {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.06-2ubuntu14.8"
        },
        {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.06-2ubuntu14.8"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
Ubuntu:22.04:LTS
grub2-signed

Package

Name
grub2-signed
Purl
pkg:deb/ubuntu/grub2-signed?arch=source&distro=jammy

Affected ranges

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

Affected versions

1.*
1.173
1.174
1.176
1.177
1.178
1.179
1.180
1.182~22.04.1
1.187.2
1.187.3~22.04.1
1.187.4~22.04.1
1.187.6
1.187.12

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.187.12+2.06-2ubuntu14.8"
        },
        {
            "binary_name": "grub-efi-arm64-signed",
            "binary_version": "1.187.12+2.06-2ubuntu14.8"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
grub2-unsigned

Package

Name
grub2-unsigned
Purl
pkg:deb/ubuntu/grub2-unsigned?arch=source&distro=jammy

Affected ranges

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

Affected versions

2.*
2.04-1ubuntu47
2.04-1ubuntu48
2.06-2ubuntu3
2.06-2ubuntu4
2.06-2ubuntu5
2.06-2ubuntu6
2.06-2ubuntu7
2.06-2ubuntu10
2.06-2ubuntu14
2.06-2ubuntu14.1
2.06-2ubuntu14.2
2.06-2ubuntu14.4
2.06-2ubuntu14.8

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.06-2ubuntu14.8"
        },
        {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.06-2ubuntu14.8"
        },
        {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.06-2ubuntu14.8"
        },
        {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.06-2ubuntu14.8"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
Ubuntu:24.04:LTS
grub2-signed

Package

Name
grub2-signed
Purl
pkg:deb/ubuntu/grub2-signed?arch=source&distro=noble

Affected ranges

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

Affected versions

1.*
1.197
1.199
1.201
1.202
1.202.2
1.202.5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.202.5+2.12-1ubuntu7.3"
        },
        {
            "binary_name": "grub-efi-arm64-signed",
            "binary_version": "1.202.5+2.12-1ubuntu7.3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
grub2-unsigned

Package

Name
grub2-unsigned
Purl
pkg:deb/ubuntu/grub2-unsigned?arch=source&distro=noble

Affected ranges

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

Affected versions

2.*
2.12~rc1-10ubuntu4
2.12~rc1-12ubuntu2
2.12-1ubuntu1
2.12-1ubuntu7
2.12-1ubuntu7.1
2.12-1ubuntu7.3

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.12-1ubuntu7.3"
        },
        {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.12-1ubuntu7.3"
        },
        {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.12-1ubuntu7.3"
        },
        {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.12-1ubuntu7.3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
Ubuntu:26.04:LTS
grub2-signed

Package

Name
grub2-signed
Purl
pkg:deb/ubuntu/grub2-signed?arch=source&distro=resolute

Affected ranges

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

Affected versions

1.*
1.214
1.215

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.215+2.14-2ubuntu1"
        },
        {
            "binary_name": "grub-efi-arm64-signed",
            "binary_version": "1.215+2.14-2ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
grub2-unsigned

Package

Name
grub2-unsigned
Purl
pkg:deb/ubuntu/grub2-unsigned?arch=source&distro=resolute

Affected ranges

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

Affected versions

2.*
2.14~git20250718.0e36779-1ubuntu4
2.14-2ubuntu1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.14-2ubuntu1"
        },
        {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.14-2ubuntu1"
        },
        {
            "binary_name": "grub-efi-amd64-unsigned",
            "binary_version": "2.14-2ubuntu1"
        },
        {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.14-2ubuntu1"
        },
        {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.14-2ubuntu1"
        },
        {
            "binary_name": "grub-efi-arm64-unsigned",
            "binary_version": "2.14-2ubuntu1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
Ubuntu:Pro:14.04:LTS
grub2

Package

Name
grub2
Purl
pkg:deb/ubuntu/grub2?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

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

Affected versions

2.*
2.00-19ubuntu2
2.00-19ubuntu3
2.00-19ubuntu4
2.00-20
2.00-21
2.00-22
2.02~beta2-5
2.02~beta2-6
2.02~beta2-7
2.02~beta2-8
2.02~beta2-9
2.02~beta2-9ubuntu1
2.02~beta2-9ubuntu1.1
2.02~beta2-9ubuntu1.2
2.02~beta2-9ubuntu1.3
2.02~beta2-9ubuntu1.4
2.02~beta2-9ubuntu1.5
2.02~beta2-9ubuntu1.6
2.02~beta2-9ubuntu1.7
2.02~beta2-9ubuntu1.8
2.02~beta2-9ubuntu1.11
2.02~beta2-9ubuntu1.12
2.02~beta2-9ubuntu1.14
2.02~beta2-9ubuntu1.15
2.02~beta2-9ubuntu1.16
2.02~beta2-9ubuntu1.17
2.02~beta2-9ubuntu1.20
2.02~beta2-9ubuntu1.21

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-common",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-coreboot",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-coreboot-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi-amd64",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi-amd64-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi-arm",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi-arm-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi-arm64",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi-arm64-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi-ia32",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-efi-ia32-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-emu",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-firmware-qemu",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-ieee1275",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-ieee1275-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-linuxbios",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-pc",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-pc-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-rescue-pc",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-theme-starfield",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-uboot",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-uboot-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-xen",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub-xen-bin",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub2",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        },
        {
            "binary_name": "grub2-common",
            "binary_version": "2.02~beta2-9ubuntu1.21"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"
grub2-signed

Package

Name
grub2-signed
Purl
pkg:deb/ubuntu/grub2-signed?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

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

Affected versions

1.*
1.22
1.23
1.24
1.25
1.26
1.27
1.30
1.31
1.32
1.33
1.34
1.34.1
1.34.2
1.34.3
1.34.4
1.34.5
1.34.6
1.34.7
1.34.8
1.34.9
1.34.13
1.34.14
1.34.16
1.34.17
1.34.18
1.34.20
1.34.22
1.34.24

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "grub-efi-amd64-signed",
            "binary_version": "1.34.24+2.02~beta2-9ubuntu1.21"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-97876.json"