UBUNTU-CVE-2026-48523

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Source

https://ubuntu.com/security/CVE-2026-48523

Import Source

https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48523.json

JSON Data

https://api.osv.dev/v1/vulns/UBUNTU-CVE-2026-48523

Upstream

CVE-2026-48523

Published

2026-05-28T16:16:00Z

Modified

2026-06-03T11:26:16Z

Severity

5.4 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N CVSS Calculator
Ubuntu - medium

Summary

[none]

Details

PyJWT is a JSON Web Token implementation in Python. From 2.9.0 to 2.12.1, there is a verifier-side algorithm allow-list bypass when jwt.decode() or jwt.decodecomplete() are called with a PyJWK key. The token header alg is checked against the caller-supplied algorithms allow-list, but signature verification is performed with the algorithm bound to the PyJWK object instead of the header algorithm. An attacker who controls a registered JWK/JWKS private key can sign with a disallowed algorithm, advertise an allowed algorithm in the JWT header, and still be accepted. The issue affects the documented PyJWKClient.getsigningkeyfrom_jwt(...) flow. This vulnerability is fixed in 2.13.0.

References

Affected packages

Ubuntu:22.04:LTS

pyjwt

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.7.1-2ubuntu2

2.*

2.1.0-1

2.3.0-1

2.3.0-1ubuntu0.1

2.3.0-1ubuntu0.2

2.3.0-1ubuntu0.3

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "2.3.0-1ubuntu0.3",
            "binary_name": "python3-jwt"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48523.json"

Ubuntu:24.04:LTS

pyjwt

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.7.0-1

2.7.0-1ubuntu0.1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "2.7.0-1ubuntu0.1",
            "binary_name": "python3-jwt"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48523.json"

Ubuntu:25.10

pyjwt

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.10.1-2

2.10.1-2ubuntu0.1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "2.10.1-2ubuntu0.1",
            "binary_name": "python3-jwt"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48523.json"

Ubuntu:26.04:LTS

pyjwt

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

2.*

2.10.1-2

2.10.1-3

2.10.1-3build1

2.10.1-4

2.10.1-4ubuntu1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "2.10.1-4ubuntu1",
            "binary_name": "python3-jwt"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48523.json"

Ubuntu:Pro:16.04:LTS

pyjwt

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.0.0-0ubuntu1

1.3.0-1

1.3.0-1ubuntu0.1

1.3.0-1ubuntu0.1+esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1.3.0-1ubuntu0.1+esm1",
            "binary_name": "python-jwt"
        },
        {
            "binary_version": "1.3.0-1ubuntu0.1+esm1",
            "binary_name": "python3-jwt"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48523.json"

Ubuntu:Pro:18.04:LTS

pyjwt

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.4.2-1.1

1.5.3+ds1-1

1.5.3+ds1-1ubuntu0.1

1.5.3+ds1-1ubuntu0.1+esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1.5.3+ds1-1ubuntu0.1+esm1",
            "binary_name": "python-jwt"
        },
        {
            "binary_version": "1.5.3+ds1-1ubuntu0.1+esm1",
            "binary_name": "python3-jwt"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48523.json"

Ubuntu:Pro:20.04:LTS

pyjwt

Package

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

Affected ranges

Type: ECOSYSTEM
Events: Introduced

0Unknown introduced version / All previous versions are affected

Affected versions

1.*

1.7.0-2

1.7.1-1

1.7.1-2ubuntu1

1.7.1-2ubuntu2

1.7.1-2ubuntu2.1

1.7.1-2ubuntu2.1+esm1

Ecosystem specific

{
    "binaries": [
        {
            "binary_version": "1.7.1-2ubuntu2.1+esm1",
            "binary_name": "python3-jwt"
        }
    ]
}

Database specific

source

"https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-48523.json"