CVE-2026-32647
Description
A flaw was found in NGINX's ngx_http_mp4_module. This Out-of-Bounds Read/Write vulnerability occurs due to improper handling of specially crafted MP4 files. A local authenticated attacker, by supplying a malicious MP4 file, can trigger a buffer over-read or overwrite in worker memory. This can lead to process termination, potentially causing a denial-of-service or, under certain conditions, achieving code execution.
Statement
This IMPORTANT vulnerability in the NGINX ngx_http_mp4_module is due to improper handling of specially crafted MP4 files. A local authenticated attacker could exploit this flaw by providing a malicious MP4 file, leading to a denial of service or potentially arbitrary code execution. Red Hat products utilizing NGINX with the ngx_http_mp4_module enabled are affected if untrusted MP4 files are processed.
Mitigation
To mitigate this issue, disable the ngx_http_mp4_module in your NGINX configuration if MP4 file processing is not required. This can be done by commenting out or removing the mp4 directive from the NGINX configuration file. After modifying the configuration, a reload or restart of the NGINX service is required for the changes to take effect.
Alternatively, restrict access to the NGINX server to trusted networks and users to prevent the upload and processing of malicious MP4 files.
Common Vulnerability Scoring System (CVSS) Score Details
Info alert:Important note
CVSS scores for open source components depend on vendor-specific factors (e.g. version or build chain). Therefore, Red Hat's score and impact rating can be different from NVD and other vendors. Red Hat remains the authoritative CVE Naming Authority (CNA) source for its products and services (see Red Hat classifications).
CVSS v3 Score Breakdown
| Red Hat | NVD | cve.org | |
|---|---|---|---|
| Base Score | 7.8 | N/A | 7.8 |
| Attack Vector | Local | N/A | Local |
| Attack Complexity | Low | N/A | Low |
| Privileges Required | Low | N/A | Low |
| User Interaction | None | N/A | None |
| Scope | Unchanged | N/A | Unchanged |
| Confidentiality | High | N/A | High |
| Integrity Impact | High | N/A | High |
| Availability Impact | High | N/A | High |
Vector
Red Hat: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
cve.org: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Understanding the Weakness (CWE)
Confidentiality
Technical Impact: Read Memory
An attacker could get secret values such as cryptographic keys, PII, memory addresses, or other information that could be used in additional attacks.
Confidentiality
Technical Impact: Bypass Protection Mechanism
Out-of-bounds memory could contain memory addresses or other information that can be used to bypass ASLR and other protection mechanisms in order to improve the reliability of exploiting a separate weakness for code execution.
Availability
Technical Impact: DoS: Crash, Exit, or Restart
An attacker could cause a segmentation fault or crash by causing memory to be read outside of the bounds of the buffer. This is especially likely when the code reads a variable amount of data and assumes that a sentinel exists to stop the read operation, such as a NUL in a string.
Other
Technical Impact: Varies by Context
The read operation could produce other undefined or unexpected results.
Acknowledgements
Red Hat would like to thank Pavel Kohout (Aisle Research) for reporting this issue.
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