PHP flaws being used in attacks

CISA lists 3 flaws in PHP products as being used in attacks, most recently on 7 Jul 2025. 1 has been used in ransomware.

What to do

1. Update every PHP product you use.Install the updates PHP offers, on every device, and restart when asked. Each flaw below has a fix or clear advice; that’s one of CISA’s conditions for listing it.
2. If someone looks after IT for you, send them this page.Many of these are in equipment you don’t see: routers, firewalls, servers, the office network. Ask them to confirm each one is fixed, or that you don’t use the product.
3. Check anything else in the lookup.Search any app, company or CVE. Not being on CISA’s list doesn’t mean safe: keep updating either way.

Every flaw, newest first

1. Being used in attacksAdded by CISA on 7 Jul 2025
   PHPMailer
   CVE-2016-10033PHPMailer Command Injection Vulnerability
   PHPMailer contains a command injection vulnerability because it fails to sanitize user-supplied input. Specifically, this issue affects the 'mail()' function of 'class.phpmailer.php' script. An attacker can exploit this issue to execute arbitrary code within the context of the application. Failed exploit attempts will result in a denial-of-service condition.
   CISA’s required actionApply mitigations per vendor instructions, follow applicable BOD 22-01 guidance for cloud services, or discontinue use of the product if mitigations are unavailable.
   CVE recordNVD
2. Being used in attacksUsed in ransomwareAdded by CISA on 25 Mar 2022
   PHP FastCGI Process Manager (FPM)
   CVE-2019-11043PHP FastCGI Process Manager (FPM) Buffer Overflow Vulnerability
   In some versions of PHP in certain configurations of FPM setup, it is possible to cause FPM module to write past allocated buffers allowing the possibility of remote code execution.
   CISA’s required actionApply updates per vendor instructions.
   CVE recordNVD
3. Being used in attacksAdded by CISA on 25 Mar 2022
   PHP
   CVE-2012-1823PHP-CGI Query String Parameter Vulnerability
   sapi/cgi/cgi_main.c in PHP, when configured as a CGI script, does not properly handle query strings, which allows remote attackers to execute arbitrary code.
   CISA’s required actionApply updates per vendor instructions.
   CVE recordNVD

From CISA’s Known Exploited Vulnerabilities catalog, updated 21 Oct 2026 (version 2026.10.21). CISA’s required actions are written for US government agencies. PHP on CISA’s site.