{"id":"CVE-2026-48490","summary":"ArduinoCore-AVR: Stack-Based Buffer Overflow in String float/double concatenation handler","details":"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.","aliases":["GHSA-fhp2-f8hw-mgpj"],"modified":"2026-09-13T03:46:01.899535005Z","published":"2026-09-11T21:00:06.071Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48490.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-120"]},"references":[{"type":"WEB","url":"https://github.com/arduino/ArduinoCore-avr/pull/622/changes/9492e146880d2b05d9cb9191f1bfb2c872a48404"},{"type":"WEB","url":"https://github.com/arduino/ArduinoCore-avr/releases/tag/1.8.8"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48490.json"},{"type":"ADVISORY","url":"https://github.com/arduino/ArduinoCore-avr/security/advisories/GHSA-fhp2-f8hw-mgpj"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48490"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/arduino/arduinocore-avr","events":[{"introduced":"0"},{"fixed":"86df345b3cf46754a5db38fb983ec2808ce31303"}],"database_specific":{"extracted_events":[{"introduced":"0"},{"fixed":"1.8.8"}],"source":["AFFECTED_FIELD","REFERENCES"]}}],"versions":["1.8.7","1.8.6","1.8.5","1.8.4","1.8.3","1.8.2","1.8.1","1.6.23","1.6.22"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48490.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V4","score":"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"}]}