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 6.86.8Trending — 3 sources updated this week
EchelonGraph scoreLOW confidence
This medium-severity CVE scores 6.8 under the CNA's CVSS (NVD's own analysis pending). EPSS exploit-prediction score not yet available (the EPSS model rescores nightly; freshly-published CVEs typically appear within 48 hours). GitHub Security Advisory data not yet ingested — confidence will rise once GHSA publishes (typical lag: hours to days for open-source ecosystem CVEs; never for infrastructure-only CVEs).
Triggered by: NVD CVSS baseline
Sources: cna:redhat
6.8
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
- Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS: 0%CVSS: 6.8Exploit: NoneExposed: 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(low)
- EG Risk
- 35(Track)EG Risk 35/100SSVC: 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%Automatability30% × 15%Action: Routine — remediate on your standard cadence. - EPSS
- 5.0%
- 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(1)
These vendors published their own advisory mentioning this CVE — often with vendor-specific remediation steps + affected product lists not in NVD.
Weakness Classification(1)
MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.
Data Freshness Timeline
(refreshed 4× in last 7d / 4× 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.
- 2026-07-23 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
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 5.0% percentile likelihood of exploitation in the next 30 days — higher percentiles indicate greater predicted risk.
What is the CVSS score of CVE-2026-6390?
CVE-2026-6390 has a CVSS v3 base score of 6.8 (NVD). The EG score is currently aggregating — additional source signals are being incorporated as they become available..
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?
EchelonGraph automatically scans your cloud infrastructure and maps CVE exposure using blast radius analysis.