UBUNTU-CVE-2026-40355

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Source
https://ubuntu.com/security/CVE-2026-40355
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40355.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-40355
Upstream
Downstream
Related
Published
2026-04-28T06:16:00Z
Modified
2026-08-05T11:30:13Z
Severity
  • 5.9 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • 7.5 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

In MIT Kerberos 5 (aka krb5) before 1.22.3, there is a NULL pointer dereference if an application calls gss_accept_sec_context() on a system with a NegoEx mechanism registered in /etc/gss/mech. An unauthenticated remote attacker can trigger this, causing the process to terminate in parse_nego_message.

References

Affected packages

Ubuntu:22.04:LTS / krb5

Package

Name
krb5
Purl
pkg:deb/ubuntu/krb5?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.19.2-2ubuntu0.8

Affected versions

1.*
1.18.3-6
1.18.3-7
1.19.2-0ubuntu1
1.19.2-1
1.19.2-2
1.19.2-2ubuntu0.1
1.19.2-2ubuntu0.2
1.19.2-2ubuntu0.3
1.19.2-2ubuntu0.4
1.19.2-2ubuntu0.5
1.19.2-2ubuntu0.6
1.19.2-2ubuntu0.7

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-kdc",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-locales",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-multidev",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-otp",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "krb5-user",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libgssrpc4",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libk5crypto3",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libkdb5-10",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libkrad0",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libkrb5-3",
            "binary_version": "1.19.2-2ubuntu0.8"
        },
        {
            "binary_name": "libkrb5support0",
            "binary_version": "1.19.2-2ubuntu0.8"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40355.json"

Ubuntu:24.04:LTS / krb5

Package

Name
krb5
Purl
pkg:deb/ubuntu/krb5?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.20.1-6ubuntu2.7

Affected versions

1.*
1.20.1-3ubuntu1
1.20.1-5build1
1.20.1-6ubuntu1
1.20.1-6ubuntu2
1.20.1-6ubuntu2.1
1.20.1-6ubuntu2.2
1.20.1-6ubuntu2.3
1.20.1-6ubuntu2.4
1.20.1-6ubuntu2.5
1.20.1-6ubuntu2.6

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-kdc",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-locales",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-multidev",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-otp",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "krb5-user",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libgssrpc4t64",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libk5crypto3",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libkdb5-10t64",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libkrad0",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libkrb5-3",
            "binary_version": "1.20.1-6ubuntu2.7"
        },
        {
            "binary_name": "libkrb5support0",
            "binary_version": "1.20.1-6ubuntu2.7"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40355.json"

Ubuntu:25.10 / krb5

Package

Name
krb5
Purl
pkg:deb/ubuntu/krb5?arch=source&distro=questing

Affected ranges

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

Affected versions

1.*
1.21.3-4ubuntu2
1.21.3-5ubuntu1
1.21.3-5ubuntu2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-kdc",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-locales",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-multidev",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-otp",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "krb5-user",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libgssrpc4t64",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libk5crypto3",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libkdb5-10t64",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libkrad0",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libkrb5-3",
            "binary_version": "1.21.3-5ubuntu2"
        },
        {
            "binary_name": "libkrb5support0",
            "binary_version": "1.21.3-5ubuntu2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40355.json"

Ubuntu:26.04:LTS / krb5

Package

Name
krb5
Purl
pkg:deb/ubuntu/krb5?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
1.22.1-2ubuntu4.1

Affected versions

1.*
1.21.3-5ubuntu2
1.22.1-2
1.22.1-2ubuntu2
1.22.1-2ubuntu3
1.22.1-2ubuntu4

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "krb5-admin-server",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-gss-samples",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-k5tls",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-kdc",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-kdc-ldap",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-kpropd",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-locales",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-multidev",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-otp",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-pkinit",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "krb5-user",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libgssapi-krb5-2",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libgssrpc4t64",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libk5crypto3",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libkadm5clnt-mit12",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libkadm5srv-mit12",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libkdb5-10t64",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libkrad0",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libkrb5-3",
            "binary_version": "1.22.1-2ubuntu4.1"
        },
        {
            "binary_name": "libkrb5support0",
            "binary_version": "1.22.1-2ubuntu4.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40355.json"