← All CVEs

CVE-2026-6390

MEDIUM 6.8

Published 2026-07-23 · Last modified 2026-08-21

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.

NO EXPLOITATION SIGNALS

No known exploitation, public exploit, or elevated probability at this time. Track for changes.

Exploitation likelihood

0.1%chance of exploitation in 30 days · 1st percentile

○ In CISA KEV ○ Public exploit / PoC

Impact if exploited

6.8CVSS 3.1 · MEDIUM

  • ConfidentialityLow
  • IntegrityHigh
  • AvailabilityHigh

What an attacker needs

  • Access: Requires local access to the host
  • Privileges: Requires a low-privilege account
  • User interaction: A user must take an action (click / open a file)
  • Complexity: No special conditions — reliably repeatable

✓ lowers the bar for an attacker · ⚠ raises it

Proof of concept & exploit code

Test against your own equipment

curl -s https://vulnpedia.com/cve/CVE-2026-6390/poc.jsonMachine-readable PoC index for this CVE (for automation).

Listed for defensive triage, patch verification, and authorized testing on systems you own. Machine-readable: /cve/CVE-2026-6390/poc.json

Affected

Vendors Red Hat

Products Red Hat Enterprise Linux 10 Red Hat Enterprise Linux 6 Red Hat Enterprise Linux 7 Red Hat Enterprise Linux 8 Red Hat Enterprise Linux 9 Red Hat Openshift Container Platform 4

Weakness (CWE)

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

CVSS vector

CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:H

All CVSS metrics

  • MEDIUM 6.8 v3.1 · CNA Primary
    CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:H
  • MEDIUM 6.8 v3.1 · NVD Secondary
    CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:L/I:H/A:H

References

Technical & other

Sources: NVD · CVE.org · EPSS