# CVE-2026-48490

## Summary

- **CVE ID:** CVE-2026-48490
- **Severity:** MEDIUM
- **CVSS Score:** 6.9 (CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N)
- **CWE:** CWE-120
- **Published:** Sep 11, 2026
- **Last Modified:** Sep 14, 2026

## Description

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.

## Affected Products

- arduino — ArduinoCore-avr (< 1.8.8)

## References

- [CNA](https://github.com/arduino/ArduinoCore-avr/security/advisories/GHSA-fhp2-f8hw-mgpj)
- [CNA](https://github.com/arduino/ArduinoCore-avr/pull/622/changes/9492e146880d2b05d9cb9191f1bfb2c872a48404)
- [CNA](https://github.com/arduino/ArduinoCore-avr/releases/tag/1.8.8)

## Exploitation Prediction (EPSS)

- **EPSS Score:** 0.39%
- **EPSS Percentile:** 33.1

---
_Exported from OnDuty AI Vulnerability Intelligence on 2026-09-18._