Cyber Resilience

CVE-2026-32647

Memory Safety in F5 Nginx Plus r32 … r36

Published
24 March 2026
Modified
15 July 2026
Patch / advisory
CVSS Score v4 8.5
Click a component to see what it means
Raw vectorCVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
EPSS Score 0.0092 57th percentile
Risk Priority 35 floored blend · peak EPSS

Summary

CVE-2026-32647 is a high-severity Out-of-bounds Read (CWE-125) vulnerability in F5 Nginx Plus. Its CVSS base score is 8.5 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 43% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

The strongest mitigations our analysis identified map to SA-11 (Developer Testing and Evaluation) and SA-8 (Security and Privacy Engineering Principles) — see the control section below for these in your framework.

Deeper analysis AI-assisted summary

Synthesised by an AI model from the NVD description and linked references — a reading aid, not an authoritative source.

CVE-2026-32647 is a vulnerability (CWE-125: Out-of-bounds Read) in the ngx_http_mp4_module of NGINX Open Source and NGINX Plus. It enables a buffer over-read or over-write in NGINX worker memory via a specially crafted MP4 file, potentially resulting in worker process termination or code execution. The flaw affects NGINX Open Source and NGINX Plus instances that are built with the ngx_http_mp4_module and have the mp4 directive enabled in the configuration file.

Exploitation requires local access (AV:L), low complexity (AC:L), and low privileges (PR:L), with no user interaction needed (UI:N) and no scope change (S:U). An attacker who can trigger processing of the malicious MP4 file by the ngx_http_mp4_module could achieve high impacts to confidentiality, integrity, and availability (C:H/I:H/A:H), yielding a CVSS v3.1 base score of 7.8.

The F5 security advisory at https://my.f5.com/manage/s/article/K000160366 provides further details on the issue. Note that software versions which have reached End of Technical Support (EoTS) are not evaluated.

EU & UK References

Vulnerability Data

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…

more

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.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
T1203 Exploitation for Client Execution Execution
Adversaries may exploit software vulnerabilities in client applications to execute code.
T1210 Exploitation of Remote Services Lateral Movement
Adversaries may exploit remote services to gain unauthorized access to internal systems once inside of a network.
T1211 Exploitation for Stealth Stealth
Adversaries may exploit vulnerabilities to evade detection by hiding activity, suppressing logging, or operating within trusted or unmonitored components.
T1212 Exploitation for Credential Access Credential Access
Adversaries may exploit software vulnerabilities in an attempt to collect credentials.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2025-53859Same product: F5 Nginx Open Source
CVE-2024-7347Same product: F5 Nginx Open Source
CVE-2026-27654Same product: F5 Nginx Open Source
CVE-2024-24990Same product: F5 Nginx Open Source
CVE-2026-42934Same product: F5 Nginx Open Source
CVE-2026-48142Same product: F5 Nginx Open Source
CVE-2026-60065Same product: F5 Nginx Plus
CVE-2026-28753Same product: F5 Nginx Open Source
CVE-2025-24497Same vendor: F5
CVE-2023-27730Same vendor: F5

Affected Assets

f5
nginx plus
r32, r33, r34, r35, r36
f5
nginx open source
1.1.19 — 1.28.3 · 1.29.0 — 1.29.7

Mitigating Controls

Mitigating Controls (NIST 800-53 r5) AI

Developer testing and evaluation directly finds out-of-bounds read flaws through static analysis, fuzzing, and dynamic bounds checks.

Secure engineering principles require bounds checking and memory-safe constructs that stop out-of-bounds reads from being introduced.

Process isolation confines the effects of an out-of-bounds read to the compromised process.

Input validation rejects malformed indices or lengths that would otherwise cause reads outside buffer bounds.

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.PS-06 mostly match
prevents

Secure-development practices such as bounds checking and memory-safe languages directly prevent out-of-bounds reads.

ID.RA-01 partial match
prevents

Vulnerability scanning and recording can discover instances of out-of-bounds reads after code is deployed.

PR.PS-02 partial match
prevents

Routine patching replaces vulnerable code containing out-of-bounds read flaws.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

finds

Security testing in development and acceptance includes fuzzing and static analysis that detect out-of-bounds read defects before release.

A.8.15 Logging partial match
finds

Logging can record evidence of an out-of-bounds read but does not prevent the weakness itself.

prevents

Secure development life cycle mandates input validation and bounds checking that directly prevent out-of-bounds reads.

prevents

Application security requirements include explicit bounds and memory-safety specifications that mitigate buffer over-reads.

prevents

Secure system architecture and engineering principles require memory-safe design patterns and runtime protections against out-of-bounds access.

prevents

Secure coding standards explicitly forbid unsafe pointer arithmetic and mandate bounds-checked reads, eliminating CWE-125.

References