CVE-2026-27784: f5 nginx open source Integer Overflow or Wraparound

Vulnerability summary

CVE-2026-27784 is a high (CVSS 8.5) Integer Overflow or Wraparound vulnerability in f5 nginx open source. EPSS estimates a 1.03% chance of exploitation in the next 30 days, higher than 63.1% of scored vulnerabilities.

Timeline

1. 24-03-2026
   PublishedVulnerability first disclosed.
2. 15-07-2026
   Last modifiedVulnerability information updated.

Description

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.

• CWE-190Integer Overflow or WraparoundThe product performs a calculation that can produce an integer overflow or wraparound when the logic assumes that the resulting value will always be larger than the original value. This occurs when an integer value is incremented to a value that is too large to store in the associated representation. When this occurs, the value may become a very small or negative number.