UBUNTU-CVE-2026-76781

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Source
https://ubuntu.com/security/CVE-2026-76781
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-76781.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-76781
Upstream
Downstream
Related
Published
2026-09-17T16:17:00Z
Modified
2026-10-09T07:45:02Z
Severity
  • 5.5 (Medium) CVSS_V3 - CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

A flaw was found in libxml2. A local user or an attacker providing a specially crafted XML catalog can trigger a NULL pointer dereference during XML catalog parsing. This occurs when a nextCatalog element lacks its mandatory catalog attribute, leading to the application crashing and causing a Denial of Service (DoS).

References

Affected packages

Ubuntu:22.04:LTS
libxml2

Package

Name
libxml2
Purl
pkg:deb/ubuntu/libxml2?arch=source&distro=jammy

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.9.13+dfsg-1ubuntu0.14

Affected versions

2.*
2.9.12+dfsg-4
2.9.12+dfsg-5
2.9.12+dfsg-6
2.9.13+dfsg-1
2.9.13+dfsg-1build1
2.9.13+dfsg-1ubuntu0.1
2.9.13+dfsg-1ubuntu0.2
2.9.13+dfsg-1ubuntu0.3
2.9.13+dfsg-1ubuntu0.4
2.9.13+dfsg-1ubuntu0.5
2.9.13+dfsg-1ubuntu0.6
2.9.13+dfsg-1ubuntu0.7
2.9.13+dfsg-1ubuntu0.8
2.9.13+dfsg-1ubuntu0.9
2.9.13+dfsg-1ubuntu0.10
2.9.13+dfsg-1ubuntu0.11
2.9.13+dfsg-1ubuntu0.12
2.9.13+dfsg-1ubuntu0.13

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "libxml2",
            "binary_version": "2.9.13+dfsg-1ubuntu0.14"
        },
        {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.13+dfsg-1ubuntu0.14"
        },
        {
            "binary_name": "python3-libxml2",
            "binary_version": "2.9.13+dfsg-1ubuntu0.14"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-76781.json"
Ubuntu:24.04:LTS
libxml2

Package

Name
libxml2
Purl
pkg:deb/ubuntu/libxml2?arch=source&distro=noble

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.9.14+dfsg-1.3ubuntu3.10

Affected versions

2.*
2.9.14+dfsg-1.3
2.9.14+dfsg-1.3build1
2.9.14+dfsg-1.3build2
2.9.14+dfsg-1.3build3
2.9.14+dfsg-1.3ubuntu1
2.9.14+dfsg-1.3ubuntu2
2.9.14+dfsg-1.3ubuntu3
2.9.14+dfsg-1.3ubuntu3.1
2.9.14+dfsg-1.3ubuntu3.2
2.9.14+dfsg-1.3ubuntu3.3
2.9.14+dfsg-1.3ubuntu3.4
2.9.14+dfsg-1.3ubuntu3.5
2.9.14+dfsg-1.3ubuntu3.6
2.9.14+dfsg-1.3ubuntu3.7
2.9.14+dfsg-1.3ubuntu3.8
2.9.14+dfsg-1.3ubuntu3.9

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "libxml2",
            "binary_version": "2.9.14+dfsg-1.3ubuntu3.10"
        },
        {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.14+dfsg-1.3ubuntu3.10"
        },
        {
            "binary_name": "python3-libxml2",
            "binary_version": "2.9.14+dfsg-1.3ubuntu3.10"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-76781.json"
Ubuntu:26.04:LTS
libxml2

Package

Name
libxml2
Purl
pkg:deb/ubuntu/libxml2?arch=source&distro=resolute

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.15.2+dfsg-0.1ubuntu0.3

Affected versions

2.*
2.14.5+dfsg-0.2
2.14.5+dfsg-0.2build1
2.15.1+dfsg-0.3
2.15.1+dfsg-0.4
2.15.1+dfsg-1
2.15.1+dfsg-2
2.15.1+dfsg-2ubuntu1
2.15.1+dfsg-2ubuntu2
2.15.2+dfsg-0.1
2.15.2+dfsg-0.1ubuntu0.1
2.15.2+dfsg-0.1ubuntu0.2

Ecosystem specific 

{
    "availability": "No subscription required",
    "binaries": [
        {
            "binary_name": "libxml2-16",
            "binary_version": "2.15.2+dfsg-0.1ubuntu0.3"
        },
        {
            "binary_name": "libxml2-source",
            "binary_version": "2.15.2+dfsg-0.1ubuntu0.3"
        },
        {
            "binary_name": "libxml2-utils",
            "binary_version": "2.15.2+dfsg-0.1ubuntu0.3"
        },
        {
            "binary_name": "python3-libxml2",
            "binary_version": "2.15.2+dfsg-0.1ubuntu0.3"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-76781.json"
Ubuntu:Pro:14.04:LTS
libxml2

Package

Name
libxml2
Purl
pkg:deb/ubuntu/libxml2?arch=source&distro=esm-infra-legacy%2Ftrusty

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.9.1+dfsg1-3ubuntu4.13+esm13

Affected versions

2.*
2.9.1+dfsg1-3ubuntu2
2.9.1+dfsg1-3ubuntu3
2.9.1+dfsg1-3ubuntu4
2.9.1+dfsg1-3ubuntu4.1
2.9.1+dfsg1-3ubuntu4.2
2.9.1+dfsg1-3ubuntu4.3
2.9.1+dfsg1-3ubuntu4.4
2.9.1+dfsg1-3ubuntu4.5
2.9.1+dfsg1-3ubuntu4.6
2.9.1+dfsg1-3ubuntu4.7
2.9.1+dfsg1-3ubuntu4.8
2.9.1+dfsg1-3ubuntu4.9
2.9.1+dfsg1-3ubuntu4.10
2.9.1+dfsg1-3ubuntu4.11
2.9.1+dfsg1-3ubuntu4.12
2.9.1+dfsg1-3ubuntu4.13
2.9.1+dfsg1-3ubuntu4.13+esm1
2.9.1+dfsg1-3ubuntu4.13+esm2
2.9.1+dfsg1-3ubuntu4.13+esm3
2.9.1+dfsg1-3ubuntu4.13+esm4
2.9.1+dfsg1-3ubuntu4.13+esm5
2.9.1+dfsg1-3ubuntu4.13+esm6
2.9.1+dfsg1-3ubuntu4.13+esm7
2.9.1+dfsg1-3ubuntu4.13+esm8
2.9.1+dfsg1-3ubuntu4.13+esm9
2.9.1+dfsg1-3ubuntu4.13+esm10
2.9.1+dfsg1-3ubuntu4.13+esm11
2.9.1+dfsg1-3ubuntu4.13+esm12

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "libxml2",
            "binary_version": "2.9.1+dfsg1-3ubuntu4.13+esm13"
        },
        {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.1+dfsg1-3ubuntu4.13+esm13"
        },
        {
            "binary_name": "python-libxml2",
            "binary_version": "2.9.1+dfsg1-3ubuntu4.13+esm13"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-76781.json"
Ubuntu:Pro:16.04:LTS
libxml2

Package

Name
libxml2
Purl
pkg:deb/ubuntu/libxml2?arch=source&distro=esm-infra-legacy%2Fxenial

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.9.3+dfsg1-1ubuntu0.7+esm14

Affected versions

2.*
2.9.2+zdfsg1-4
2.9.2+zdfsg1-4ubuntu1
2.9.2+zdfsg1-4ubuntu2
2.9.2+zdfsg1-4ubuntu3
2.9.3+dfsg1-1
2.9.3+dfsg1-1ubuntu0.1
2.9.3+dfsg1-1ubuntu0.2
2.9.3+dfsg1-1ubuntu0.3
2.9.3+dfsg1-1ubuntu0.4
2.9.3+dfsg1-1ubuntu0.5
2.9.3+dfsg1-1ubuntu0.6
2.9.3+dfsg1-1ubuntu0.7
2.9.3+dfsg1-1ubuntu0.7+esm1
2.9.3+dfsg1-1ubuntu0.7+esm2
2.9.3+dfsg1-1ubuntu0.7+esm3
2.9.3+dfsg1-1ubuntu0.7+esm4
2.9.3+dfsg1-1ubuntu0.7+esm5
2.9.3+dfsg1-1ubuntu0.7+esm6
2.9.3+dfsg1-1ubuntu0.7+esm7
2.9.3+dfsg1-1ubuntu0.7+esm8
2.9.3+dfsg1-1ubuntu0.7+esm9
2.9.3+dfsg1-1ubuntu0.7+esm10
2.9.3+dfsg1-1ubuntu0.7+esm11
2.9.3+dfsg1-1ubuntu0.7+esm12
2.9.3+dfsg1-1ubuntu0.7+esm13

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "libxml2",
            "binary_version": "2.9.3+dfsg1-1ubuntu0.7+esm14"
        },
        {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.3+dfsg1-1ubuntu0.7+esm14"
        },
        {
            "binary_name": "python-libxml2",
            "binary_version": "2.9.3+dfsg1-1ubuntu0.7+esm14"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-76781.json"
Ubuntu:Pro:18.04:LTS
libxml2

Package

Name
libxml2
Purl
pkg:deb/ubuntu/libxml2?arch=source&distro=esm-infra%2Fbionic

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.9.4+dfsg1-6.1ubuntu1.9+esm9

Affected versions

2.*
2.9.4+dfsg1-4ubuntu1
2.9.4+dfsg1-5ubuntu1
2.9.4+dfsg1-5ubuntu2
2.9.4+dfsg1-5.1ubuntu1
2.9.4+dfsg1-5.2ubuntu1
2.9.4+dfsg1-6.1ubuntu1
2.9.4+dfsg1-6.1ubuntu1.2
2.9.4+dfsg1-6.1ubuntu1.3
2.9.4+dfsg1-6.1ubuntu1.4
2.9.4+dfsg1-6.1ubuntu1.5
2.9.4+dfsg1-6.1ubuntu1.6
2.9.4+dfsg1-6.1ubuntu1.7
2.9.4+dfsg1-6.1ubuntu1.8
2.9.4+dfsg1-6.1ubuntu1.9
2.9.4+dfsg1-6.1ubuntu1.9+esm1
2.9.4+dfsg1-6.1ubuntu1.9+esm2
2.9.4+dfsg1-6.1ubuntu1.9+esm3
2.9.4+dfsg1-6.1ubuntu1.9+esm4
2.9.4+dfsg1-6.1ubuntu1.9+esm5
2.9.4+dfsg1-6.1ubuntu1.9+esm6
2.9.4+dfsg1-6.1ubuntu1.9+esm7
2.9.4+dfsg1-6.1ubuntu1.9+esm8

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "libxml2",
            "binary_version": "2.9.4+dfsg1-6.1ubuntu1.9+esm9"
        },
        {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.4+dfsg1-6.1ubuntu1.9+esm9"
        },
        {
            "binary_name": "python-libxml2",
            "binary_version": "2.9.4+dfsg1-6.1ubuntu1.9+esm9"
        },
        {
            "binary_name": "python3-libxml2",
            "binary_version": "2.9.4+dfsg1-6.1ubuntu1.9+esm9"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-76781.json"
Ubuntu:Pro:20.04:LTS
libxml2

Package

Name
libxml2
Purl
pkg:deb/ubuntu/libxml2?arch=source&distro=esm-infra%2Ffocal

Affected ranges

Type
ECOSYSTEM
Events
Introduced
0 Unknown introduced version / All previous versions are affected
Fixed
2.9.10+dfsg-5ubuntu0.20.04.10+esm6

Affected versions

2.*
2.9.4+dfsg1-7ubuntu3
2.9.4+dfsg1-7ubuntu5
2.9.4+dfsg1-8ubuntu1
2.9.4+dfsg1-8ubuntu2
2.9.4+dfsg1-8ubuntu3
2.9.10+dfsg-1ubuntu3
2.9.10+dfsg-4build1
2.9.10+dfsg-5
2.9.10+dfsg-5ubuntu0.20.04.1
2.9.10+dfsg-5ubuntu0.20.04.2
2.9.10+dfsg-5ubuntu0.20.04.3
2.9.10+dfsg-5ubuntu0.20.04.4
2.9.10+dfsg-5ubuntu0.20.04.5
2.9.10+dfsg-5ubuntu0.20.04.6
2.9.10+dfsg-5ubuntu0.20.04.7
2.9.10+dfsg-5ubuntu0.20.04.8
2.9.10+dfsg-5ubuntu0.20.04.9
2.9.10+dfsg-5ubuntu0.20.04.10
2.9.10+dfsg-5ubuntu0.20.04.10+esm1
2.9.10+dfsg-5ubuntu0.20.04.10+esm2
2.9.10+dfsg-5ubuntu0.20.04.10+esm3
2.9.10+dfsg-5ubuntu0.20.04.10+esm4
2.9.10+dfsg-5ubuntu0.20.04.10+esm5

Ecosystem specific 

{
    "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro",
    "binaries": [
        {
            "binary_name": "libxml2",
            "binary_version": "2.9.10+dfsg-5ubuntu0.20.04.10+esm6"
        },
        {
            "binary_name": "libxml2-utils",
            "binary_version": "2.9.10+dfsg-5ubuntu0.20.04.10+esm6"
        },
        {
            "binary_name": "python-libxml2",
            "binary_version": "2.9.10+dfsg-5ubuntu0.20.04.10+esm6"
        },
        {
            "binary_name": "python3-libxml2",
            "binary_version": "2.9.10+dfsg-5ubuntu0.20.04.10+esm6"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-76781.json"