NGINX Plus and NGINX Open Source have a vulnerability in the ngx_http_rewrite_module module. This vulnerability exists when the rewrite directive is followed by a rewrite, if, or set directive and an unnamed Perl-Compatible Regular Expression (PCRE) capture (for example, $1, $2) with a replacement string that includes a question mark (?). An unauthenticated attacker along with conditions beyond its 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. 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 7 products from f5, from f5, from f5 and 4 others, 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.
2026-05-13T16:16:50.190
2026-07-15T02:21:38.583
Modified
CVSSv3.1: 8.1 (HIGH)
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Application | f5 | dos | ≤ 4.7.0 | Yes |
| Application | f5 | dos | 4.8.0 | Yes |
| Application | f5 | nginx_gateway_fabric | ≤ 1.6.2 | Yes |
| Application | f5 | nginx_gateway_fabric | ≤ 2.5.1 | Yes |
| Application | f5 | nginx_ingress_controller | ≤ 3.7.2 | Yes |
| Application | f5 | nginx_ingress_controller | ≤ 4.0.1 | Yes |
| Application | f5 | nginx_ingress_controller | ≤ 5.4.1 | Yes |
| Application | f5 | nginx_instance_manager | ≤ 2.21.1 | Yes |
| Application | f5 | nginx_open_source | ≤ 1.30.0 | Yes |
| Application | f5 | nginx_plus | ≤ r36 | Yes |
| Application | f5 | waf | ≤ 4.16.0 | Yes |
| Application | f5 | waf | ≤ 5.8.0 | Yes |
| Application | f5 | waf | ≤ 5.12.1 | 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.