{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-42854", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-04-30T16:44:48.378Z", "datePublished": "2026-05-12T21:56:33.437Z", "dateUpdated": "2026-05-13T14:24:52.597Z" }, "containers": { "cna": { "title": "arduino-esp32: Stack buffer overflow in WebServer multipart boundary parsing leads to remote crash potential RCE", "problemTypes": [ { "descriptions": [ { "cweId": "CWE-121", "lang": "en", "description": "CWE-121: Stack-based Buffer Overflow", "type": "CWE" } ] } ], "metrics": [ { "cvssV3_1": { "attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 9.8, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H", "version": "3.1" } } ], "references": [ { "name": "https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j", "tags": [ "x_refsource_CONFIRM" ], "url": "https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j" } ], "affected": [ { "vendor": "espressif", "product": "arduino-esp32", "versions": [ { "version": "< 3.3.8", "status": "affected" } ] } ], "providerMetadata": { "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-05-12T21:56:33.437Z" }, "descriptions": [ { "lang": "en", "value": "arduino-esp32 is an Arduino core for the ESP32, ESP32-S2, ESP32-S3, ESP32-C3, ESP32-C6 and ESP32-H2 microcontrollers. Prior to 3.3.8, the WebServer multipart form parser in arduino-esp32 allocates a Variable Length Array (VLA) on the stack whose size is derived from an attacker-controlled HTTP header field (Content-Type: multipart/form-data; boundary=...) without enforcing any length limit. Sending a boundary string longer than ~8000 characters overflows the 8192-byte task stack of the loopTask, causing a crash and potential remote code execution. This vulnerability is fixed in 3.3.8." } ], "source": { "advisory": "GHSA-8cmm-3887-r32j", "discovery": "UNKNOWN" } }, "adp": [ { "references": [ { "url": "https://github.com/espressif/arduino-esp32/security/advisories/GHSA-8cmm-3887-r32j", "tags": [ "exploit" ] } ], "metrics": [ { "other": { "type": "ssvc", "content": { "timestamp": "2026-05-13T14:24:33.796662Z", "id": "CVE-2026-42854", "options": [ { "Exploitation": "poc" }, { "Automatable": "yes" }, { "Technical Impact": "total" } ], "role": "CISA Coordinator", "version": "2.0.3" } } } ], "title": "CISA ADP Vulnrichment", "providerMetadata": { "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-05-13T14:24:52.597Z" } } ] } }