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.

Metrics

Attack Vector Network

Attack Complexity Low

Privileges Required None

Attack Requirements None

User Interaction None

Vulnerable System Confidentiality Impact None

Vulnerable System Integrity Impact High

Vulnerable System Availability Impact None

Subsequent System Confidentiality Impact None

Subsequent System Integrity Impact None

Subsequent System Availability Impact None

No CVSS v3.1

No CVSS v3.0

No CVSS v2

This CVE is not in the KEV list.

The EPSS score is 0.00086.

Exploitation poc

Automatable yes

Technical Impact partial

Affected Vendors & Products

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Advisories
Source ID Title
EUVD EUVD EUVD-2025-19427 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.
Fixes

Solution

No solution given by the vendor.

Workaround

No workaround given by the vendor.

References
Link Providers
https://github.com/ESP32Async/ESPAsyncWebServer/blob/1095dfd1ecf1a903aede29854232af1b24f089b1/src/AsyncWebHeader.cpp#L6-L32 cve-icon cve-icon
https://github.com/ESP32Async/ESPAsyncWebServer/pull/211 cve-icon cve-icon
https://github.com/ESP32Async/ESPAsyncWebServer/security/advisories/GHSA-87j8-6f7g-h8wh cve-icon cve-icon
History

Fri, 27 Jun 2025 21:15:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'poc', 'Technical Impact': 'partial'}, 'version': '2.0.3'}

Fri, 27 Jun 2025 20:15:00 +0000

Type Values Removed Values Added
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.
Title ESPAsyncWebServer Vulnerable to CRLF Injection in AsyncWebHeader.cpp
Weaknesses CWE-113
CWE-93
References
Metrics cvssV4_0

{'score': 8.7, 'vector': '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'}
cve-icon MITRE

Status: PUBLISHED

Assigner: GitHub_M

Published:

Updated: 2025-06-27T20:19:14.457Z

Reserved: 2025-06-25T13:41:23.086Z

Link: CVE-2025-53094

cve-icon Vulnrichment

Updated: 2025-06-27T20:19:04.852Z

cve-icon NVD

Status : Awaiting Analysis

Published: 2025-06-27T20:15:35.173

Modified: 2025-06-30T18:38:23.493

Link: CVE-2025-53094

cve-icon Redhat

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cve-icon OpenCVE Enrichment

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