Linux Distros Unpatched Vulnerability : CVE-2025-59420

high Nessus Plugin ID 265880

Synopsis

The Linux/Unix host has one or more packages installed with a vulnerability that the vendor indicates will not be patched.

Description

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

- Authlib is a Python library which builds OAuth and OpenID Connect servers. Prior to version 1.6.4, Authlib's JWS verification accepts tokens that declare unknown critical header parameters (crit), violating RFC 7515 mustunderstand semantics. An attacker can craft a signed token with a critical header (for example, bork or cnf) that strict verifiers reject but Authlib accepts. In mixedlanguage fleets, this enables splitbrain verification and can lead to policy bypass, replay, or privilege escalation. This issue has been patched in version 1.6.4. (CVE-2025-59420)

Note that Nessus relies on the presence of the package as reported by the vendor.

Solution

There is no known solution at this time.

See Also

https://security-tracker.debian.org/tracker/CVE-2025-59420

Plugin Details

Severity: High

ID: 265880

File Name: unpatched_CVE_2025_59420.nasl

Version: 1.1

Type: local

Agent: unix

Family: Misc.

Published: 9/25/2025

Updated: 9/25/2025

Supported Sensors: Frictionless Assessment Agent, Nessus Agent, Agentless Assessment, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 4.4

CVSS v2

Risk Factor: Medium

Base Score: 6.4

Temporal Score: 4.7

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

CVSS Score Source: CVE-2025-59420

CVSS v3

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.5

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:U/RL:O/RC:C

Vulnerability Information

CPE: p-cpe:/a:debian:debian_linux:python-authlib, cpe:/o:debian:debian_linux:11.0, cpe:/o:debian:debian_linux:13.0, cpe:/o:debian:debian_linux:12.0

Required KB Items: Host/local_checks_enabled, Host/cpu, global_settings/vendor_unpatched, Host/OS/identifier

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 9/22/2025

Reference Information

CVE: CVE-2025-59420