Linux Distros Unpatched Vulnerability : CVE-2026-9648

critical Nessus Plugin ID 320677

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.

- The crypton-x509-validation Haskell library fails to enforce X.509 NameConstraints, allowing TLS clients to accept certificates whose Subject Alternative Names fall outside the issuing CA's permitted subtrees.
This oversight enables an attacker who compromises a name-constrained sub-CA to impersonate domains beyond its intended scope. (CVE-2026-9648)

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-2026-9648

Plugin Details

Severity: Critical

ID: 320677

File Name: unpatched_CVE_2026_9648.nasl

Version: 1.1

Type: Local

Agent: unix

Family: Misc.

Published: 6/11/2026

Updated: 6/11/2026

Supported Sensors: Nessus Agent, Nessus

Risk Information

VPR

Risk Factor: Medium

Score: 6.0

CVSS v2

Risk Factor: High

Base Score: 7.5

Temporal Score: 6.4

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

CVSS Score Source: CVE-2026-9648

CVSS v3

Risk Factor: Critical

Base Score: 9.1

Temporal Score: 8.3

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

Temporal Vector: CVSS:3.0/E:U/RL:U/RC:C

Vulnerability Information

CPE: cpe:/o:debian:debian_linux:13.0, cpe:/o:debian:debian_linux:14.0, p-cpe:/a:debian:debian_linux:haskell-crypton-x509-validation

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

Exploit Ease: No known exploits are available

Vulnerability Publication Date: 6/11/2026

Reference Information

CVE: CVE-2026-9648