CVE-2026-27784: F5 Nginx Open Source

High severity, CVSS 7.8. EPSS: 1% chance of exploitation in the next 30 days.

The 32-bit implementation of NGINX Open Source has a vulnerability in the ngx_http_mp4_module module, which might allow an attacker to over-read or over-write NGINX worker memory resulting in its termination, using a specially crafted MP4 file. The issue only affects 32-bit NGINX Open Source if it is built with the ngx_http_mp4_module module and the mp4 directive is used in the configuration file. Additionally, the attack is possible only if an attacker can trigger the processing of a specially crafted MP4 file with the ngx_http_mp4_module module. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Affected products

• F5 Nginx Open Source: from 1.1.19, before 1.28.3 (fixed in 1.28.3); from 1.29.0, before 1.29.7 (fixed in 1.29.7)

Published 2026-03-24. Last modified 2026-07-15.