Out-of-bounds Read in F5 nginx Open Source

CVE-2026-32647

NGINX Open Source and NGINX Plus have a vulnerability in the ngx_http_mp4_module module, which might allow an attacker to trigger a buffer over-read or over-write to the NGINX worker memory resulting in its termination or possibly code execution, using a specially crafted MP4 file. This issue affects NGINX Open Source and NGINX Plus 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.

Vulnerability class: Buffer Overflow

Published · last modified .

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H.

EPSS exploit prediction

EPSS: 0.003 (26.4th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 26th percentile — 26.4% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2026-32647: fell from 0.009 to 0.003.

EPSS over last 30 days · oldest: 0.009 · newest: 0.003 · change: -0.006

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-32647?
CVE-2026-32647 is a high-severity vulnerability in F5 nginx Open Source, classified under Out-of-bounds Read. CVSS score: 7.8/10. Published 2026-03-24.
How severe is CVE-2026-32647?
High severity. CVSS v3 base score is 7.8 out of 10.