A vulnerability exists in NGINX Plus and NGINX Open Source when a map directive uses regex matching and a string expression 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.
This vulnerability carries a HIGH severity rating with a CVSS v3.1 score of 8.1, indicating it can be exploited remotely over the network but requires specific conditions to be met without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 4 products from f5, from f5, from f5 and 1 other, organizations running these solutions should prioritize assessment and patching.
Reported in 2026, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.
2026-07-15T15:16:33.480
2026-08-10T15:28:01.940
Analyzed
CVSSv3.1: 8.1 (HIGH)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | f5 | nginx_gateway_fabric | ≤ 1.6.2 | Yes |
| Application | f5 | nginx_gateway_fabric | < 2.6.7 | Yes |
| Application | f5 | nginx_ingress_controller | ≤ 3.7.2 | Yes |
| Application | f5 | nginx_ingress_controller | < 5.5.3 | Yes |
| Application | f5 | nginx_ingress_controller | < 2026-lts-r4 | Yes |
| Application | f5 | nginx_ingress_controller | 4.0.0 | Yes |
| Application | f5 | nginx_ingress_controller | 4.0.1 | Yes |
| Application | f5 | nginx_plus | < 37.0.3.1 | Yes |
| Application | f5 | nginx_plus | < r36 | Yes |
| Application | f5 | nginx_plus | r36 | Yes |
| Application | f5 | nginx_plus | r36 | Yes |
| Application | f5 | nginx_plus | r36 | Yes |
| Application | f5 | nginx_plus | r36 | Yes |
| Application | f5 | nginx_plus | r36 | Yes |
| Application | f5 | nginx_plus | r36 | Yes |
| Application | f5 | nginx_plus | r36 | Yes |
| Application | f5 | waf | ≤ 4.16.0 | Yes |
| Application | f5 | waf | ≤ 5.8.0 | Yes |
| Application | f5 | waf | < 5.13.4 | Yes |
SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For f5's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.