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.
CVE-2026-6390
MEDIUMPre-NVD 6.86.8—Trending — 4 sources updated this week
EchelonGraph scoreHIGH confidence
Score 6.8 from GitHub Security Advisory published 2026-07-23. a secondary CVSS source baseline 6.8; sources differ by 0.0.
Triggered by: GitHub Security Advisory CVSS
Sources: epss, ghsa, secondary
6.8EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 0%CVSS: 6.8Exploit: None knownExposed: 0
No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.
- CVSS v3
- 6.8
- EG Score
- 6.8(high)
- EG Risk
- 31(Track)EG Risk 31/100SSVC: Track
EG Risk is EchelonGraph's 0–100 priority score: it fuses intrinsic severity with real-world exploitation and automatability so you can rank equal-severity CVEs and fix the most dangerous first. Higher = act sooner. Distinct from the 0–10 EG Score (severity).
How it’s computedSeverity68% × 45%Exploitation0% × 40%Automatability0% × 15%Action: Routine — remediate on your standard cadence. - EPSS PROB
- 0%
- EPSS %ILE
- 1%
- KEV
- Not listed
Published
July 23, 2026
Last Modified
July 23, 2026
Advisory Details (2)
Auto-updated Jul 23, 2026Patch available. Sources: redhat.
redhat
2458767 – (CVE-2026-6390) CVE-2026-6390 nano: GNU nano: Arbitrary memory writes, information disclosure, or denial of service via format string vulnerability in error handling.
https://bugzilla.redhat.com/show_bug.cgi?id=2458767Vendor Advisories for CVE-2026-6390(2)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
- CVE-2026-6390Microsoft Security Response Center (MSRC)Medium
Nano: gnu nano: arbitrary memory writes, information disclosure, or denial of service via format string vulnerability in error handling.
- GHSA-cgrj-mh7v-v4c8GitHub Security AdvisoriesMedium
A flaw was found in GNU nano's multi-buffer error message handling. When a user opens multiple...
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 13× in last 7d / 13× in last 30d)
Each row is a source pipeline that fetched or updated this CVE on that date, with what changed. For example, "NVD update" means NVD published or revised its analysis for this CVE; "MITRE cvelistV5" means we ingested or refreshed it from the CNA feed. Most recent first.
- 2026-07-28 00:18 UTCGHSA enrichment
- 2026-07-27 01:39 UTCEG score recompute
- 2026-07-27 01:39 UTCGHSA enrichment
- 2026-07-26 03:21 UTCEG score recompute
- 2026-07-26 03:21 UTCGHSA enrichment
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-25 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-24 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 14:18 UTCEPSS rescore
- 2026-07-23 04:50 UTCEG score recompute
- 2026-07-23 04:49 UTCMITRE cvelistV5first tracked
Related CVEs(same CWE)
Same CWE
10 shownCWE-134
- CVE-2008-7228EG 10.0HIGH
- CVE-2009-1210EG 10.0EPSS p96HIGH
- CVE-2008-6520EG 10.0EPSS p91HIGH
- CVE-2008-6519EG 10.0EPSS p92HIGH
- CVE-2008-5982EG 10.0EPSS p94HIGH
- CVE-2008-3533EG 10.0EPSS p97HIGH
- CVE-2008-3116EG 10.0EPSS p92HIGH
- CVE-2008-0764EG 10.0EPSS p94HIGH
- CVE-2007-5561EG 10.0EPSS p94HIGH
- CVE-2007-1006EG 10.0HIGH
Frequently asked(5)
What is CVE-2026-6390?
CVE-2026-6390 is a medium vulnerability published on July 23, 2026. 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…
When was CVE-2026-6390 disclosed?
CVE-2026-6390 was first published in the National Vulnerability Database on July 23, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-6390 actively exploited?
CVE-2026-6390 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 0% probability of exploitation in the next 30 days, which ranks it in the top 98.7% of all scored CVEs.
What is the CVSS score of CVE-2026-6390?
CVE-2026-6390 has a CVSS v3 base score of 6.8 (NVD).
How do I remediate CVE-2026-6390?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-6390, EchelonGraph cross-links them in the Vendor Advisories panel below — those typically contain the canonical remediation steps, fixed version numbers, and any vendor-specific mitigations.
Dependency Blast Radius
Explore the affected products and dependency analysis for CVE-2026-6390
Is Your Infrastructure Affected by CVE-2026-6390?
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