UBUNTU-CVE-2026-40611

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Source
https://ubuntu.com/security/CVE-2026-40611
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40611.json
JSON Data
https://api.test.osv.dev/v1/vulns/UBUNTU-CVE-2026-40611
Upstream
Published
2026-04-21T18:16:00Z
Modified
2026-06-30T18:17:39.000231339Z
Severity
  • 8.8 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H CVSS Calculator
  • 8.8 (High) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

Let's Encrypt client and ACME library written in Go (Lego). Prior to 4.34.0, the webroot HTTP-01 challenge provider in lego is vulnerable to arbitrary file write and deletion via path traversal. A malicious ACME server can supply a crafted challenge token containing ../ sequences, causing lego to write attacker-influenced content to any path writable by the lego process. This vulnerability is fixed in 4.34.0.

References

Affected packages

Ubuntu:18.04:LTS
golang-github-xenolf-lego

Package

Name
golang-github-xenolf-lego
Purl
pkg:deb/ubuntu/golang-github-xenolf-lego?arch=source&distro=bionic

Affected ranges

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

Affected versions

0.*
0.3.1-5

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-xenolf-lego-dev",
            "binary_version": "0.3.1-5"
        },
        {
            "binary_name": "lego",
            "binary_version": "0.3.1-5"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40611.json"
Ubuntu:20.04:LTS
golang-github-xenolf-lego

Package

Name
golang-github-xenolf-lego
Purl
pkg:deb/ubuntu/golang-github-xenolf-lego?arch=source&distro=focal

Affected ranges

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

Affected versions

0.*
0.3.1-5
2.*
2.7.2+dfsg-1
3.*
3.2.0-1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-xenolf-lego-dev",
            "binary_version": "3.2.0-1"
        },
        {
            "binary_name": "lego",
            "binary_version": "3.2.0-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40611.json"
Ubuntu:22.04:LTS
golang-github-xenolf-lego

Package

Name
golang-github-xenolf-lego
Purl
pkg:deb/ubuntu/golang-github-xenolf-lego?arch=source&distro=jammy

Affected ranges

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

Affected versions

3.*
3.2.0-3.1
4.*
4.1.3-3ubuntu1
4.1.3-3ubuntu1.22.04.1

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-xenolf-lego-dev",
            "binary_version": "4.1.3-3ubuntu1.22.04.1"
        },
        {
            "binary_name": "lego",
            "binary_version": "4.1.3-3ubuntu1.22.04.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40611.json"
Ubuntu:25.10
golang-github-xenolf-lego

Package

Name
golang-github-xenolf-lego
Purl
pkg:deb/ubuntu/golang-github-xenolf-lego?arch=source&distro=questing

Affected ranges

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

Affected versions

4.*
4.9.1-2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-xenolf-lego-dev",
            "binary_version": "4.9.1-2"
        },
        {
            "binary_name": "lego",
            "binary_version": "4.9.1-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40611.json"
Ubuntu:26.04:LTS
golang-github-xenolf-lego

Package

Name
golang-github-xenolf-lego
Purl
pkg:deb/ubuntu/golang-github-xenolf-lego?arch=source&distro=resolute

Affected ranges

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

Affected versions

4.*
4.9.1-2
4.9.1-3
4.9.1-4

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-xenolf-lego-dev",
            "binary_version": "4.9.1-4"
        },
        {
            "binary_name": "lego",
            "binary_version": "4.9.1-4"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40611.json"
Ubuntu:Pro:24.04:LTS
golang-github-xenolf-lego

Package

Name
golang-github-xenolf-lego
Purl
pkg:deb/ubuntu/golang-github-xenolf-lego?arch=source&distro=esm-apps%2Fnoble

Affected ranges

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

Affected versions

4.*
4.9.1-1build1
4.9.1-2
4.9.1-2ubuntu0.24.04.1
4.9.1-2ubuntu0.24.04.2
4.9.1-2ubuntu0.24.04.2+esm1
4.9.1-2ubuntu0.24.04.3
4.9.1-2ubuntu0.24.04.3+esm1
4.9.1-2ubuntu0.24.04.3+esm2

Ecosystem specific 

{
    "binaries": [
        {
            "binary_name": "golang-github-xenolf-lego-dev",
            "binary_version": "4.9.1-2ubuntu0.24.04.3+esm2"
        },
        {
            "binary_name": "lego",
            "binary_version": "4.9.1-2ubuntu0.24.04.3+esm2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-40611.json"