NGINX

CVE-2026-27784: NGINX ngx_http_mp4_module vulnerability

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.

Published

ExploitedNot in CISA KEV
Ransomware useNot reportedPer CISA
SeverityHIGHCVSS 4.0 8.5
EPSS1.0%Chance of exploitation in 30 days
Public exploitNot tracked
FixAvailable

Automatic summary from the vendor's CVE record. We haven't written a full analysis of this vulnerability yet.

Affected and fixed versions

Product / branchFixed in
NGINX Open Source 1.291.29.7 or later
NGINX Open Source 1.11.28.3 or later

Always confirm against the vendor advisory, which lists every fixed hotfix.

What it is

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.

Sources

KEV status, EPSS score and vendor data refreshed automatically, last on 12 Oct 2026.

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