What’s Vulnerable › Vulnerabilities

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

• Severity: high (CVSS 7.5 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 1.9% probability of exploitation in the next 30 days
• Public exploit or detection template: yes
• Published: 2024-04-29 · updated 2026-06-17
• Weakness: CWE-400

Description

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 products

• PHP: from 8.3.0 before 8.3.5 — fixed in 8.3.5

How to fix

Upgrade to a fixed version: PHP 8.3.5. Check the vendor advisory for mitigations.

References

• http://www.openwall.com/lists/oss-security/2024/04/12/11
• https://github.com/php/php-src/security/advisories/GHSA-fjp9-9hwx-59fq
• https://security.netapp.com/advisory/ntap-20240510-0011/
• http://www.openwall.com/lists/oss-security/2024/04/12/11
• https://github.com/php/php-src/security/advisories/GHSA-fjp9-9hwx-59fq
• https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/KJZK3X6B7FBE32FETDSMRLJXTFTHKWSY/
• https://security.netapp.com/advisory/ntap-20240510-0011/

Get alerted when CVE-2024-2757 or the next vulnerability affects your stack