CVE-2026-6390 Nano: gnu nano: arbitrary memory writes, information disclosure, or denial of service via format string vulnerability in error handling.

Description

A flaw was found in GNU nano's multi-buffer error message handling. When a user opens multiple files at startup and one triggers an ALERT-level error, a specially crafted filename containing printf format specifiers can be reinterpreted. This format string vulnerability may allow an attacker to achieve stack information disclosure, cause a denial of service (crash), or potentially perform arbitrary memory writes.

Exploitable with local access to the machine, with an ordinary account and if a user takes an action; an attacker can seriously compromise confidentiality, integrity or availability.

Attack vector

Local

Attack complexity

Low

Privileges required

Low

Interaction

Required

Scope

Unchanged

Confidentiality

Low

Integrity

High

Availability

High

Affected products and versions