{"id":"CVE-2026-62966","aliases":[],"cve":{"records":[{"id":"CVE-2026-62966","source":"GitHub_M","state":"PUBLISHED","reasons":[],"replacements":[],"disputed":false,"unsupportedWhenAssigned":false,"reserved":"2026-07-14T22:48:09.779Z","published":"2026-10-30T20:53:37.292Z","modified":"2026-10-30T20:53:37.292Z"}],"publishers":[{"name":"GitHub_M","role":"CNA","organizationId":"a0819718-46f1-4df5-94e2-005712e83aaa","modified":"2026-10-30T20:53:37.292Z"}],"references":[{"url":"https://github.com/ESP32Async/ESPAsyncWebServer/security/advisories/GHSA-8m8p-vhxc-jmjw","tags":["x_refsource_CONFIRM"],"source":"GitHub_M"},{"url":"https://github.com/ESP32Async/ESPAsyncWebServer/commit/4efbd35e597d91f01749f2d4a14bb78fba8ea02e","tags":["x_refsource_MISC"],"source":"GitHub_M"},{"url":"https://github.com/ESP32Async/ESPAsyncWebServer/tree/v3.11.2","tags":["x_refsource_MISC"],"source":"GitHub_M"}],"weaknesses":[{"id":"CWE-476","description":"CWE-476: NULL Pointer Dereference","source":"GitHub_M"},{"id":"CWE-672","description":"CWE-672: Operation on a Resource after Expiration or Release","source":"GitHub_M"}],"applicability":[],"prioritization":[]},"title":"ESPAsyncWebServer multipart parser has null-pointer write","titleSource":"GitHub_M","descriptionSource":"GitHub_M","description":"ESPAsyncWebServer is an asynchronous HTTP and WebSocket server library for ESP32, ESP8266, RP2040 and RP2350. Prior to version 3.11.2, the multipart parser in `src/WebRequest.cpp` frees `_itemBuffer` and sets it to NULL when `BOUNDARY_OR_DATA` matches the closing boundary of a file part, before confirming the following terminator, while leaving `_itemIsFile` true. If the next byte is neither the final closing dashes nor a clean CRLF, the `DASH3_OR_RETURN2` or `EXPECT_FEED2` rewind branch re-injects provisionally consumed bytes through `itemWriteByte`. Because `_itemIsFile` remains true, `_itemBuffer`[`_itemBufferIndex`++] writes through a null pointer. On ESP32 this causes a `StoreProhibited` exception, panic and device reboot, producing remote denial of service. A route with a non-trivial body/upload handler, such as a file-upload or web-OTA endpoint, must be present. This issue is fixed in version 3.11.2.","score":7.5,"severity":"high","published":"2026-10-30T20:53:37.292Z","modified":"2026-10-30T20:53:37.292Z","withdrawn":false,"knownExploited":false,"affected":[],"products":[{"vendor":"ESP32Async","name":"ESPAsyncWebServer","platforms":[],"versions":[{"version":"< 3.11.2","status":"affected"}],"cpes":[],"source":"GitHub_M","url":"https://www.cve.org/CVERecord?id=CVE-2026-62966"}],"remediation":[],"references":["https://github.com/ESP32Async/ESPAsyncWebServer/security/advisories/GHSA-8m8p-vhxc-jmjw","https://github.com/ESP32Async/ESPAsyncWebServer/commit/4efbd35e597d91f01749f2d4a14bb78fba8ea02e","https://github.com/ESP32Async/ESPAsyncWebServer/tree/v3.11.2"],"sources":[{"name":"CVE","id":"CVE-2026-62966","modified":"2026-10-30T20:53:37.292Z","url":"https://www.cve.org/CVERecord?id=CVE-2026-62966"}],"assessments":[{"source":"GitHub_M","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","score":7.5}],"sourceAffected":[],"observedAt":"2026-10-30T21:32:12.834Z","kev":{"status":"not-listed","checkedAt":"2026-10-31T10:20:31.211Z"},"coverage":[{"source":"NVD","status":"available","checkedAt":"2026-10-30T21:45:34.254Z","attemptedAt":"2026-10-30T21:45:34.254Z"},{"source":"GHSA","status":"no-result","checkedAt":"2026-10-30T21:45:34.251Z","attemptedAt":"2026-10-30T21:45:34.251Z"},{"source":"EUVD","status":"no-result","checkedAt":"2026-10-30T21:45:34.242Z","attemptedAt":"2026-10-30T21:45:34.242Z"},{"source":"EPSS","status":"no-result","checkedAt":"2026-10-30T21:45:33.515Z","attemptedAt":"2026-10-30T21:45:33.515Z"}],"evidence":[{"source":"NVD","id":"CVE-2026-62966","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-62966","modified":"2026-10-30T21:17:15.257","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","checkedAt":"2026-10-30T21:45:34.254Z"}],"aiSummary":{"text":"ESPAsyncWebServer versions prior to 3.11.2 have a null-pointer write vulnerability in the multipart parser, potentially causing a denial of service. An attacker must have access to a route with a non-trivial body/upload handler. The weakness is a null pointer dereference and operation on a resource after expiration or release.","model":"@cf/meta/llama-3.3-70b-instruct-fp8-fast","generatedAt":"2026-10-31T05:01:14.546Z","sources":[{"name":"CVE","url":"https://www.cve.org/CVERecord?id=CVE-2026-62966"}]}}