Detections
Analytics

Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS : PyJWT vulnerabilities (USN-8823-1)

high Nessus Plugin ID 350973

Synopsis

The remote Ubuntu host is missing one or more security updates.

Description

The remote Ubuntu 16.04 LTS / 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS / 26.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8823-1 advisory.

 It was discovered that PyJWT incorrectly handled certain URIs when using PyJWKClient. A remote attacker could possibly use this issue to perform server-side request forgery (SSRF) or expose sensitive local files. This issue only affected Ubuntu 22.04 LTS, Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48522)

 It was discovered that PyJWT incorrectly verified cryptographic signatures when decoding tokens with PyJWK keys. A remote attacker could possibly use this issue to bypass signature verification and forge valid JSON Web Tokens. This issue only affected Ubuntu 26.04 LTS. (CVE-2026-48523)

 It was discovered that PyJWT incorrectly handled unknown key identifiers in PyJWKClient. A remote attacker could possibly use this issue to cause PyJWT to make excessive network requests, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48524)

 It was discovered that PyJWT incorrectly handled payload decoding during detached JWS token verification.
 A remote attacker could possibly use this issue to cause PyJWT to consume excessive resources, resulting in a denial of service. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-48525)

 It was discovered that PyJWT incorrectly validated JSON Web Keys when decoding tokens with both HMAC and asymmetric algorithms enabled. A remote attacker could possibly use this issue to forge valid tokens, resulting in an authentication bypass. (CVE-2026-48526)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

Solution

Update the affected python-jwt and / or python3-jwt packages.

See Also

https://ubuntu.com/security/notices/USN-8823-1

Plugin Details

Severity: High

ID: 350973

File Name: ubuntu_USN-8823-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 9/29/2026

Updated: 9/29/2026

Supported Sensors: Frictionless Assessment AWS, Frictionless Assessment Azure, Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Continuous Assessment, Tenable Cloud Security, Tenable Self-Hosted Container Security, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.3

Percentile: 53.61

CVSS v2

Risk Factor: High

Base Score: 7.1

Temporal Score: 5.6

Vector: CVSS2#AV:N/AC:H/Au:N/C:C/I:C/A:N

CVSS Score Source: CVE-2026-48526

CVSS v3

Risk Factor: High

Base Score: 7.4

Temporal Score: 6.7

Vector: CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N

Temporal Vector: CVSS:3.0/E:P/RL:O/RC:C

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:16.04:-:lts, cpe:/o:canonical:ubuntu_linux:18.04:-:lts, cpe:/o:canonical:ubuntu_linux:20.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, cpe:/o:canonical:ubuntu_linux:24.04:-:lts, cpe:/o:canonical:ubuntu_linux:26.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:python-jwt, p-cpe:/a:canonical:ubuntu_linux:python3-jwt

Required KB Items: Host/cpu, Host/Debian/dpkg-l, Host/Ubuntu, Host/Ubuntu/release

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 9/25/2026

Vulnerability Publication Date: 5/28/2026

Reference Information

CVE: CVE-2026-48522, CVE-2026-48523, CVE-2026-48524, CVE-2026-48525, CVE-2026-48526

USN: 8823-1