CVE-2024-2757

PHP mb_encode_mimeheader runs endlessly for some inputs

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.

Affected

PHP Group · PHP

CVSS v3.1 PHP

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

EPSS

1.92% chance of exploitation in the next 30 days, 80th percentile

Published

2024-04-29

Updated

2025-11-04

Proof-of-concept exploits (1)

• php/php-src/security/advisories/GHSA-fjp9-9hwx-59fq

Security advisories

• https://security.netapp.com/advisory/ntap-20240510-0011

References

• CVE Record
• NVD entry