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Fencer Vulns
medium 6.8

CVE-2026-6390 json

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

published 2026-07-23 3 mo ago modified 2026-11-05 3 d ago also EUVD-2026-47874

cvss
6.8
version 3.1, CNA
cisa kev
Not listed
not in CISA's catalog
epss
0.2%
EPSS 0.2% chance of exploitation in 30 days, percentile 4%
public exploits
0
none known

Summary

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.

Patch / fix

  • nano Debian 14 9.0-1

debian advisories DEBIAN-CVE-2026-6390

  • nano Ubuntu 22.04 LTS 6.2-1ubuntu0.2
  • nano Ubuntu 24.04 LTS 7.2-2ubuntu0.2
  • nano Ubuntu 25.10 8.4-1ubuntu0.1
  • nano Ubuntu 26.04 LTS 8.7.1-1ubuntu0.1

ubuntu advisories UBUNTU-CVE-2026-6390

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • nano openSUSE Tumbleweed 9.3-1.1

opensuse advisories openSUSE-SU-2026:12247-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2026-6390 updated cvss 6.8

nano: GNU nano: Arbitrary memory writes, information disclosure, or denial of service via format string vulnerability in error handling.

  • Red Hat Enterprise Linux 6 nano Red Hat Enterprise Linux 7 nano Red Hat Enterprise Linux 8 nano Red Hat Enterprise Linux 9 nano Red Hat Enterprise Linux 10 nano Red Hat OpenShift Container Platform 4 openshift/ose-rhel-coreos-8, openshift/ose-rhel-coreos-9
    +1 more products
    Red Hat OpenShift Container Platform 5 openshift/ose-rhel-coreos-9
    affected: workaround, no fix available “Fix deferred”

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

CISA SSVC

Exploitation
none
Automatable
no
Technical impact
total
Assessed
3 mo ago

Exploit prediction

0.15% chance of exploitation in the next 30 days, higher than 4% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
CNA 3.1 6.8 CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:H

Affected products

  • Red Hat Red Hat Enterprise Linux 10
  • Red Hat Red Hat Enterprise Linux 6
  • Red Hat Red Hat Enterprise Linux 7
  • Red Hat Red Hat Enterprise Linux 8
  • Red Hat Red Hat Enterprise Linux 9
  • Red Hat Red Hat OpenShift Container Platform 4
  • Red Hat Red Hat OpenShift Container Platform 5

Classification

Weakness
  • CWE-134 Use of Externally-Controlled Format String

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.