---
id: CVE-2026-48490
title: >-
  ArduinoCore-avr contains the source code and configuration files of the
  Arduino AVR Boards platform
summary: >-
  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…
severity: medium
cvss: 6.9
cvssVector: '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
vendor: arduino
product: ArduinoCore-avr
affected:
  - ArduinoCore-avr < 1.8.8
published: '2026-09-11'
updated: '2026-09-14'
sourceUpdated: '2026-09-14T19:17:23.083'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-48490'
references:
  - url: >-
      https://github.com/arduino/ArduinoCore-avr/pull/622/changes/9492e146880d2b05d9cb9191f1bfb2c872a48404
    label: security-advisories@github.com
  - url: 'https://github.com/arduino/ArduinoCore-avr/releases/tag/1.8.8'
    label: security-advisories@github.com
  - url: >-
      https://github.com/arduino/ArduinoCore-avr/security/advisories/GHSA-fhp2-f8hw-mgpj
    label: security-advisories@github.com
tags:
  - nvd
  - cve.org
epss: 0.00392
epssPercentile: 0.33256
ssvc:
  exploitation: none
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-14T17:06:22.605242Z'
cvssSource: cna
ingestedAt: '2026-09-14T11:11:19.879Z'
---

## Overview

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.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.