Red Hat nano Multi-buffer Error Message format string

Summaryinfo

A vulnerability, which was classified as problematic, was found in Red Hat nano. This impacts an unknown function of the component Multi-buffer Error Message Handler. Executing a manipulation can lead to format string. This vulnerability appears as CVE-2026-6390. The attack requires local access. There is no available exploit.

Detailsinfo

A vulnerability has been found in Red Hat nano (affected version not known) and classified as problematic. This vulnerability affects some unknown functionality of the component Multi-buffer Error Message Handler. The manipulation with an unknown input leads to a format string vulnerability. The CWE definition for the vulnerability is CWE-134. The product uses a function that accepts a format string as an argument, but the format string originates from an external source. As an impact it is known to affect confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at access.redhat.com. This vulnerability was named CVE-2026-6390 since 04/15/2026. The exploitation appears to be easy. The attack needs to be approached locally. Successful exploitation requires user interaction by the victim. There are neither technical details nor an exploit publicly available. The current price for an exploit might be approx. USD $5k-$25k (estimation calculated on 07/23/2026).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2026-47874). Once again VulDB remains the best source for vulnerability data.

Productinfo

Vendor

• Red Hat

Name

• nano

License

• open-source

Website

• Vendor: https://www.redhat.com/

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Once again VulDB remains the best source for vulnerability data.

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