Denial of Service Vulnerability in ESPAsyncWebServer for ESP32, ESP8266, RP2040 and RP2350
CVE-2026-62966

7.5HIGH

Key Information:

Vendor

Esp32async

Status
Espasyncwebserver
Vendor
CVE Published:
30 October 2026

What is CVE-2026-62966?

A vulnerability in ESPAsyncWebServer, an HTTP and WebSocket server library for ESP32, ESP8266, RP2040, and RP2350, allows an attacker to trigger a denial of service. This occurs when the multipart parser mishandles file uploads, leading to a null pointer dereference. If a crafted request is made with a non-trivial body that matches certain conditions, it can cause a 'StoreProhibited' exception, resulting in a device panic and subsequent reboot. This vulnerability is mitigated in version 3.11.2 of the library, highlighting the importance of updating to secure versions.

Affected Version(s)

ESPAsyncWebServer < 3.11.2

References

https://github.com/ESP32Async/ESPAsyncWebServer/security/...
x_refsource_CONFIRM
https://github.com/ESP32Async/ESPAsyncWebServer/commit/4e...
x_refsource_MISC
https://github.com/ESP32Async/ESPAsyncWebServer/tree/v3.11.2
x_refsource_MISC

CVSS V3.1

Score:
7.5
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
None
Attack Vector:
Network
Attack Complexity:
Low
Privileges Required:
None
User Interaction:
None
Scope:
Unchanged

Timeline

  • Vulnerability published

  • Vulnerability Reserved

.