CVE-2026-93479
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Heap Buffer Overflow in NGINX Plus and NGINX Open Source
Vulnerability report for CVE-2026-93479, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-10-14
Last updated on: 2026-10-14
Assigner: F5 Networks
Description
Description
A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and the root directive or access log format references the map's regex capture variables before referencing the map output variable. Alternatively, the same result could be achieved by using a non-cacheable variable in a string expression under certain conditions. An unauthenticated attacker along with conditions beyond their control can exploit this vulnerability by sending crafted HTTP requests. This may cause a heap buffer overflow in the NGINX worker process leading to a restart. Additionally, attackers can execute code on systems with Address Space Layout Randomization (ASLR) disabled or when the attacker can bypass ASLR.
Impact:
This vulnerability may allow remote attackers to cause a denial-of-service (DoS) on the NGINX system or to possibly trigger a code execution. There is no control plane exposure; this is a data plane issue only.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
CVSS Scores
EPSS Scores
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| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| F5 | NGINX | Plus 37.1.0 |
| F5 | NGINX | Plus 37.0.0 |
| F5 | NGINX | Plus R36 |
| F5 | NGINX | Plus R35 |
| F5 | NGINX | Plus R34 |
| F5 | NGINX | Plus R33 |
| F5 | NGINX | Open Source 1.31.2 |
| F5 | NGINX | Open Source 1.30.0 |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-122 | A heap overflow condition is a buffer overflow, where the buffer that can be overwritten is allocated in the heap portion of memory, generally meaning that the buffer was allocated using a routine such as malloc(). |
