Vulnerability in Red Hat Enterprise Linux 10

CVE-2026-6390

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.

Published · last modified .

CVSS v3 metric

CVSS v3 base score 6.8 (Medium). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:H.

EPSS exploit prediction

EPSS: 0.002 (4.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 4th percentile — 4.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-6390: held from 0.002 to 0.002.

EPSS over last 30 days · oldest: 0.002 · newest: 0.002 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-6390?
CVE-2026-6390 is a medium-severity vulnerability in Red Hat Enterprise Linux 10, classified under Use of Externally-Controlled Format String. CVSS score: 6.8/10. Published 2026-07-23.
How severe is CVE-2026-6390?
Medium severity. CVSS v3 base score is 6.8 out of 10.