CVE-2024-2757 HIGH

CVE-2024-2757: PHP mb_encode_mimeheader runs endlessly for some inputs

Vendor Php Group
Product PHP
Published April 29, 2024
Last update November 4, 2025

CVSS base score

7.5/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

What the vulnerability does

01Description

In PHP 8.3.* before 8.3.5, function mb_encode_mimeheader() runs endlessly for some inputs that contain long strings of non-space characters followed by a space. This could lead to a potential DoS attack if a hostile user sends data to an application that uses this function.

Key dates

02Disclosure timeline

April 29, 2024 CVE published
November 4, 2025 Record updated