CVE-2026-93479 vulnerability in F5 Networks Products
Published on October 14, 2026
NGINX map directive and regex matching vulnerability
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.
Vulnerability Analysis
CVE-2026-93479 can be exploited with network access, and does not require authorization privileges or user interaction. This vulnerability is consided to have a high level of attack complexity. The potential impact of an exploit of this vulnerability is considered to be very high.
Weakness Type
Heap-based Buffer Overflow
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().
Products Associated with CVE-2026-93479
stack.watch emails you whenever new vulnerabilities are published in F5 Networks Nginx Plus or F5 Networks Nginx Open Source. Just hit a watch button to start following.
Affected Versions
F5 NGINX Plus:- Version 37.1.0 and below 37.1.0.1 is affected.
- Version 37.0.0 and below 37.0.5.1 is affected.
- Version R36 and below * is affected.
- Version R35 and below * is affected.
- Version R34 and below * is affected.
- Version R33 and below * is affected.
- Version 1.31.2 and below 1.31.7 is affected.
- Version 1.30.0 and below 1.30.6 is affected.