CVE-2026-48490

MEDIUMPre-NVD 6.96.9—
EchelonGraph scoreMEDIUM confidence

This medium-severity CVE scores 6.9 under a secondary CVSS source (NVD's own analysis pending). EPSS exploit probability: 0.7%, top 50% of all CVEs by exploit prediction. 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: epss, secondary
6.9EG
EchelonGraph verdictMonitorLow exploitation likelihood right now — keep watching.
  • Lower severity and no public exploit yet
CISA-KEV: Not listedEPSS PROB: 1%CVSS: 6.9Exploit: None knownExposed: 0

No vendor fix yet — apply a workaround or compensating control (WAF / firewall / segmentation) and watch for a patch.

ArduinoCore-avr contains the source code and configuration files of the Arduino AVR Boards platform. A vulnerability in versions prior to 1.8.8 allows an attacker to trigger a stack-based buffer overflow when concatenating floating-point values of sufficiently large magnitude onto an Arduino String object. By passing values near the extremes of the float or double range to String::concat(float), String::concat(double), String::operator+=(), or the + operator with a float/double operand, dtostrf() writes beyond the fixed-size stack buffer, causing memory corruption and denial of service. Under specific conditions, this could enable arbitrary code execution on AVR-based Arduino boards. The fix is included starting from the 1.8.8 release.

CVSS v3
6.9
EG Score
6.9(medium)
EG Risk
46(Track)
EG Risk 46/100SSVC: 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 computed
Severity69% × 45%
Exploitation1% × 40%
Automatability100% × 15%
Action: Routine — remediate on your standard cadence.
EPSS PROB
1%
EPSS %ILE
50%
KEV
Not listed

Published

September 11, 2026

Last Modified

September 14, 2026

Advisory Details (3)

Auto-updated Sep 11, 2026
Patch available. Sources: github_pr, github_release, github.
github_release Patch Available

1.8.8

Patch available: arduino/ArduinoCore-avr 1.8.8

https://github.com/arduino/ArduinoCore-avr/releases/tag/1.8.8
github_pr Patch Available

String::concat increase buffer size to fit float/double value

Patch available: arduino/ArduinoCore-avr 1.8.8 (PR #622 merged 2026-05-21)

https://github.com/arduino/ArduinoCore-avr/pull/622/changes/9492e146880d2b05d9cb9191f1bfb2c872a48404
github Patch Available

ArduinoCore-AVR: Stack-Based Buffer Overflow in String float/double concatenation handler · Advisory · arduino/ArduinoCore-avr · GitHub

https://github.com/arduino/ArduinoCore-avr/security/advisories/GHSA-fhp2-f8hw-mgpj

Weakness Classification(1)

MITRE Common Weakness Enumeration — the root-cause categories this CVE belongs to.

Data Freshness Timeline

(refreshed 10× in last 7d / 23× 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.

  1. 2026-09-25 08:48 UTCEG score recompute
  2. 2026-09-24 07:32 UTCEG score recompute
  3. 2026-09-23 17:53 UTCEPSS rescore
  4. 2026-09-23 06:15 UTCEG score recompute
  5. 2026-09-22 04:58 UTCEG score recompute
  6. 2026-09-21 03:42 UTCEG score recompute
  7. 2026-09-20 20:16 UTCEPSS rescore
  8. 2026-09-20 02:25 UTCEG score recompute
  9. 2026-09-19 01:08 UTCEG score recompute
  10. 2026-09-18 19:28 UTCEPSS rescore
  11. 2026-09-17 23:52 UTCEG score recompute
  12. 2026-09-16 22:21 UTCEG score recompute
  13. 2026-09-16 14:08 UTCEPSS rescore
  14. 2026-09-16 05:15 UTCEPSS rescore
  15. 2026-09-15 20:48 UTCEG score recompute
  16. 2026-09-14 19:22 UTCEG score recompute
  17. 2026-09-14 18:28 UTCEG score recompute
  18. 2026-09-13 23:54 UTCEG score recompute
  19. 2026-09-13 16:47 UTCEPSS rescore
  20. 2026-09-12 22:38 UTCEG score recompute
  21. 2026-09-11 21:21 UTCEG score recompute
  22. 2026-09-11 21:14 UTCEG score recompute
  23. 2026-09-11 21:13 UTCMITRE cvelistV5first tracked

Related CVEs(same CWE)

Frequently asked(5)

What is CVE-2026-48490?
CVE-2026-48490 is a medium vulnerability published on September 11, 2026. ArduinoCore-avr contains the source code and configuration files of the Arduino AVR Boards platform. A vulnerability in versions prior to 1.8.8 allows an attacker to trigger a stack-based buffer overflow when concatenating floating-point values of sufficiently large magnitude onto an Arduino String…
When was CVE-2026-48490 disclosed?
CVE-2026-48490 was first published in the National Vulnerability Database on September 11, 2026, with the most recent update on September 14, 2026. EchelonGraph re-ingests CVE updates from NVD on a 2-hour cycle, so this page reflects the latest published state.
Is CVE-2026-48490 actively exploited?
CVE-2026-48490 is not currently on CISA's Known Exploited Vulnerabilities catalog. FIRST EPSS estimates a 1% probability of exploitation in the next 30 days, which ranks it in the top 50.3% of all scored CVEs.
What is the CVSS score of CVE-2026-48490?
CVE-2026-48490 has a CVSS v3 base score of 6.9 (NVD).
How do I remediate CVE-2026-48490?
Patch to the fixed version published by the affected vendor. Where vendor advisories exist for CVE-2026-48490, 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

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