Use of Externally-Controlled Format String Affecting nano package, versions [0,]
Threat Intelligence
The probability is the direct output of the EPSS model, and conveys an overall sense of the threat of exploitation in the wild. The percentile measures the EPSS probability relative to all known EPSS scores. Note: This data is updated daily, relying on the latest available EPSS model version. Check out the EPSS documentation for more details.
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- published25 Jul 2026
- disclosed22 Jul 2026
- creditUnknown
Introduced: 22 Jul 2026
CVE-2026-6390 (opens in a new tab)How to fix?
There is no fixed version for nano.
Overview
Affected versions of this package are vulnerable to Use of Externally-Controlled Format String via the error handling process. An attacker can cause information disclosure, denial of service, or potentially arbitrary memory writes by supplying a crafted filename containing printf format specifiers when multiple files are opened at startup and one triggers an ALERT-level error. This is only exploitable if the application is compiled with multi-buffer support and without the NANO_TINY option.
Workaround
This vulnerability can be mitigated by avoiding opening untrusted files, especially those with filenames containing printf format specifiers (e.g., %s, %p, %n).