Detections
Analytics

Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS : Authlib vulnerabilities (USN-8557-1)

high Nessus Plugin ID 327649

Synopsis

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

Description

The remote Ubuntu 22.04 LTS / 24.04 LTS / 26.04 LTS host has a package installed that is affected by multiple vulnerabilities as referenced in the USN-8557-1 advisory.

 Jay Neiva and Mauro Carrillo discovered that Authlib did not properly validate cryptographic keys embedded in JWT headers. An attacker could possibly use this issue to forge trusted tokens, resulting in authentication and authorization bypass. (CVE-2026-27962)

 Jay Neiva and Mauro Carrillo discovered that Authlib incorrectly handled RSA1_5 encrypted tokens. An attacker could possibly use this issue to recover sensitive encrypted information, resulting in information disclosure. (CVE-2026-28490)

 Jay Neiva and Mauro Carrillo discovered that Authlib did not properly reject unsupported cryptographic algorithms when validating OpenID Connect ID tokens. An attacker could possibly use this issue to bypass token integrity checks, resulting in authentication bypass. (CVE-2026-28498)

 Johnny Deuss discovered that Authlib did not provide cross-site request forgery protection for the OAuth cache feature in its Starlette integration. An attacker could possibly use this issue to perform unauthorized OAuth actions, resulting in cross-site request forgery. This issue only affected Ubuntu 24.04 LTS and Ubuntu 26.04 LTS. (CVE-2026-41425)

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 python3-authlib package.

See Also

https://ubuntu.com/security/notices/USN-8557-1

Plugin Details

Severity: High

ID: 327649

File Name: ubuntu_USN-8557-1.nasl

Version: 1.1

Type: Local

Agent: unix

Published: 7/17/2026

Updated: 7/17/2026

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

Risk Information

VPR

Risk Factor: Medium

Score: 5

Percentile: 94.39

CVSS v2

Risk Factor: High

Base Score: 7.8

Temporal Score: 6.1

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

CVSS Score Source: CVE-2026-28498

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.7

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

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

CVSS v4

Risk Factor: High

Base Score: 8.3

Threat Score: 6.9

Threat Vector: CVSS:4.0/E:P

Vector: CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:N/VC:H/VI:L/VA:N/SC:N/SI:N/SA:N

CVSS Score Source: CVE-2026-28490

Vulnerability Information

CPE: cpe:/o:canonical:ubuntu_linux:26.04:-:lts, cpe:/o:canonical:ubuntu_linux:22.04:-:lts, p-cpe:/a:canonical:ubuntu_linux:python3-authlib, cpe:/o:canonical:ubuntu_linux:24.04:-:lts

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

Exploit Available: true

Exploit Ease: Exploits are available

Patch Publication Date: 7/16/2026

Vulnerability Publication Date: 3/16/2026

Reference Information

CVE: CVE-2026-27962, CVE-2026-28490, CVE-2026-28498, CVE-2026-41425

USN: 8557-1