UBUNTU-CVE-2026-49265

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Source
https://ubuntu.com/security/CVE-2026-49265
Import Source
https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49265.json
JSON Data
https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-49265
Upstream
Published
2026-10-13T16:17:00Z
Modified
2026-10-17T12:58:33Z
Severity
  • 6.8 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N CVSS Calculator
  • Ubuntu - medium
Summary
[none]
Details

OAuthLib is an implementation of the OAuth request-signing logic for Python 3.6+. From 3.0.0 until 4.0.0, OAuthLib's PKCE checks in oauthlib/oauth2/rfc6749/grant_types/authorization_code.py compare attacker-supplied code_verifier values with stored challenges using ordinary string equality in code_challenge_method_plain and code_challenge_method_s256. Because the comparison can return after a length difference or the first mismatching character, repeated token endpoint measurements can reveal common-prefix timing information that could potentially allow recovery of the code_verifier, unauthorized access-token acquisition, and account takeover. Practical exploitation requires an intercepted, single-use authorization code and enough measurements to overcome real-world network noise; the local timing benchmark does not establish practical remote account takeover, so the weakness remains a defense-in-depth concern. This issue is fixed in version 4.0.0.

References

Affected packages

Ubuntu:16.04:LTS
python-oauthlib

Package

Name
python-oauthlib
Purl
pkg:deb/ubuntu/python-oauthlib?arch=source&distro=xenial

Affected ranges

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

Affected versions

1.*
1.0.0-1
1.0.3-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python-oauthlib",
            "binary_version":  "1.0.3-1"
        },
        {
            "binary_name":  "python3-oauthlib",
            "binary_version":  "1.0.3-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49265.json"
Ubuntu:18.04:LTS
python-oauthlib

Package

Name
python-oauthlib
Purl
pkg:deb/ubuntu/python-oauthlib?arch=source&distro=bionic

Affected ranges

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

Affected versions

2.*
2.0.1-1
2.0.4-1
2.0.6-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python-oauthlib",
            "binary_version":  "2.0.6-1"
        },
        {
            "binary_name":  "python3-oauthlib",
            "binary_version":  "2.0.6-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49265.json"
Ubuntu:20.04:LTS
python-oauthlib

Package

Name
python-oauthlib
Purl
pkg:deb/ubuntu/python-oauthlib?arch=source&distro=focal

Affected ranges

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

Affected versions

2.*
2.1.0-1
3.*
3.1.0-1ubuntu1
3.1.0-1ubuntu2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-oauthlib",
            "binary_version":  "3.1.0-1ubuntu2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49265.json"
Ubuntu:22.04:LTS
python-oauthlib

Package

Name
python-oauthlib
Purl
pkg:deb/ubuntu/python-oauthlib?arch=source&distro=jammy

Affected ranges

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

Affected versions

3.*
3.1.0-2
3.1.1-1
3.2.0-1
3.2.0-1ubuntu0.1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-oauthlib",
            "binary_version":  "3.2.0-1ubuntu0.1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49265.json"
Ubuntu:24.04:LTS
python-oauthlib

Package

Name
python-oauthlib
Purl
pkg:deb/ubuntu/python-oauthlib?arch=source&distro=noble

Affected ranges

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

Affected versions

3.*
3.2.2-1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-oauthlib",
            "binary_version":  "3.2.2-1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49265.json"
Ubuntu:26.04:LTS
python-oauthlib

Package

Name
python-oauthlib
Purl
pkg:deb/ubuntu/python-oauthlib?arch=source&distro=resolute

Affected ranges

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

Affected versions

3.*
3.2.2-3
3.3.1-1
3.3.1-1build1

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-oauthlib",
            "binary_version":  "3.3.1-1build1"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49265.json"
Ubuntu:26.10
python-oauthlib

Package

Name
python-oauthlib
Purl
pkg:deb/ubuntu/python-oauthlib?arch=source&distro=stonking

Affected ranges

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

Affected versions

3.*
3.3.1-1build1
3.3.1-2

Ecosystem specific 

{
    "binaries":  [
        {
            "binary_name":  "python3-oauthlib",
            "binary_version":  "3.3.1-2"
        }
    ]
}

Database specific

source 
"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-49265.json"