reactphp http up to 1.11.0 Browser handleData buffer overflow

Summaryinfo

A vulnerability labeled as problematic has been found in reactphp http up to 1.11.0. Impacted is the function ClientRequestStream::handleData of the component Browser. Executing a manipulation can lead to buffer overflow. This vulnerability is handled as CVE-2026-104827. The attack can be executed remotely. There is not any exploit available. The affected component should be upgraded.

Detailsinfo

A vulnerability was found in reactphp http up to 1.11.0. It has been declared as problematic. This vulnerability affects the function ClientRequestStream::handleData of the component Browser. The manipulation with an unknown input leads to a buffer overflow vulnerability. The CWE definition for the vulnerability is CWE-120. The product copies an input buffer to an output buffer without verifying that the size of the input buffer is less than the size of the output buffer, leading to a buffer overflow. As an impact it is known to affect availability. CVE summarizes:

react/http is an event-driven, streaming HTTP client and server implementation for ReactPHP. From 1.0.0 until 1.11.1, React\Http\Browser uses ClientRequestStream::handleData() to append response-header bytes to an internal buffer without enforcing a size limit. A remote server can send a valid status line and partial header, withhold the \r\n\r\n or \n\n header terminator, and continue streaming data so the buffer grows for the life of the connection. Applications that fetch attacker-controlled or attacker-influenced URLs, including URLs reached through redirects, can exhaust PHP memory_limit and crash the event-loop or worker process. Confidentiality and integrity are unaffected. This issue is fixed in version 1.11.1.

The advisory is available at github.com. This vulnerability was named CVE-2026-104827 since 10/02/2026. The exploitation appears to be easy. The attack can be initiated remotely. No form of authentication is required for a successful exploitation. Technical details are known, but there is no available exploit.

Upgrading to version 1.11.1 eliminates this vulnerability.

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Productinfo

Type

• JavaScript Library

Vendor

• reactphp

Name

• http

Version

• 1.0
• 1.1
• 1.2
• 1.3
• 1.4
• 1.5
• 1.6
• 1.7
• 1.8
• 1.9
• 1.10
• 1.11.0

Website

• Product: https://github.com/reactphp/http/

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