{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-62966", "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "state": "PUBLISHED", "assignerShortName": "GitHub_M", "dateReserved": "2026-07-14T22:48:09.779Z", "datePublished": "2026-10-30T20:53:37.292Z", "dateUpdated": "2026-10-30T20:53:37.292Z"}, "containers": {"cna": {"title": "ESPAsyncWebServer multipart parser has null-pointer write", "problemTypes": [{"descriptions": [{"cweId": "CWE-476", "lang": "en", "description": "CWE-476: NULL Pointer Dereference", "type": "CWE"}]}, {"descriptions": [{"cweId": "CWE-672", "lang": "en", "description": "CWE-672: Operation on a Resource after Expiration or Release", "type": "CWE"}]}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}}], "references": [{"name": "https://github.com/ESP32Async/ESPAsyncWebServer/security/advisories/GHSA-8m8p-vhxc-jmjw", "tags": ["x_refsource_CONFIRM"], "url": "https://github.com/ESP32Async/ESPAsyncWebServer/security/advisories/GHSA-8m8p-vhxc-jmjw"}, {"name": "https://github.com/ESP32Async/ESPAsyncWebServer/commit/4efbd35e597d91f01749f2d4a14bb78fba8ea02e", "tags": ["x_refsource_MISC"], "url": "https://github.com/ESP32Async/ESPAsyncWebServer/commit/4efbd35e597d91f01749f2d4a14bb78fba8ea02e"}, {"name": "https://github.com/ESP32Async/ESPAsyncWebServer/tree/v3.11.2", "tags": ["x_refsource_MISC"], "url": "https://github.com/ESP32Async/ESPAsyncWebServer/tree/v3.11.2"}], "affected": [{"vendor": "ESP32Async", "product": "ESPAsyncWebServer", "versions": [{"version": "< 3.11.2", "status": "affected"}]}], "providerMetadata": {"orgId": "a0819718-46f1-4df5-94e2-005712e83aaa", "shortName": "GitHub_M", "dateUpdated": "2026-10-30T20:53:37.292Z"}, "descriptions": [{"lang": "en", "value": "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."}], "source": {"advisory": "GHSA-8m8p-vhxc-jmjw", "discovery": "UNKNOWN"}}}}

{}

{"affected": [{"affectedData": [{"product": "ESPAsyncWebServer", "vendor": "ESP32Async", "versions": [{"status": "affected", "version": "< 3.11.2"}]}], "source": "security-advisories@github.com"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "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."}], "id": "CVE-2026-62966", "lastModified": "2026-10-30T21:17:15.257", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "NONE", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 3.6, "source": "security-advisories@github.com", "type": "Secondary"}]}, "published": "2026-10-30T21:17:15.137", "references": [{"source": "security-advisories@github.com", "url": "https://github.com/ESP32Async/ESPAsyncWebServer/commit/4efbd35e597d91f01749f2d4a14bb78fba8ea02e"}, {"source": "security-advisories@github.com", "url": "https://github.com/ESP32Async/ESPAsyncWebServer/security/advisories/GHSA-8m8p-vhxc-jmjw"}, {"source": "security-advisories@github.com", "url": "https://github.com/ESP32Async/ESPAsyncWebServer/tree/v3.11.2"}], "sourceIdentifier": "security-advisories@github.com", "vulnStatus": "Deferred", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-476"}, {"lang": "en", "value": "CWE-672"}], "source": "security-advisories@github.com", "type": "Primary"}]}

{}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "semver", "value": "[0,3.11.2)"}}], "enrichment": {"confidence": 100.0, "confidence_source": "matching", "scores": [{"score": 100.0, "source": "matching"}]}, "original": {"product": "ESPAsyncWebServer", "source": "cna", "vendor": "ESP32Async"}, "product": "espasyncwebserver", "vendor": "esp32async"}], "created": "2026-10-30T22:45:14.056064+00:00", "updated": "2026-10-30T22:45:14.533727+00:00", "vendors": ["esp32async", "esp32async$PRODUCT$espasyncwebserver"]}