Description
ESPAsyncWebServer is an asynchronous HTTP and WebSocket server library for ESP32, ESP8266, RP2040 and RP2350. In versions up to and including 3.7.8, a CRLF (Carriage Return Line Feed) injection vulnerability exists in the construction and output of HTTP headers within `AsyncWebHeader.cpp`. Unsanitized input allows attackers to inject CR (`\r`) or LF (`\n`) characters into header names or values, leading to arbitrary header or response manipulation. Manipulation of HTTP headers and responses can enable a wide range of attacks, making the severity of this vulnerability high. A fix is available at pull request 211 and is expected to be part of version 3.7.9.
References (3)
Scores
CVSS v4
8.7
EPSS
0.0033
EPSS Percentile
56.0%
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:H/VA:N/SC:N/SI:N/SA:N
CISA SSVC
Vulnrichment
Exploitation
poc
Automatable
yes
Technical Impact
partial
Details
CWE
CWE-113
CWE-93
Status
published
Products (1)
ESP32Async/ESPAsyncWebServer
<= 3.7.8
Published
Jun 27, 2025
Tracked Since
Feb 18, 2026