Medium · published October 14, 2026
Description
NGINX JavaScript (njs) has a vulnerability where the built-in njs engine leaks a libxml2 parser context when xml.parse() fails. The failure path did not register cleanup and the context was not released for the lifetime of the process. An unauthenticated attacker may send requests with malformed XML and can cause unbounded memory growth in long-lived NGINX worker processes.
Impact
This vulnerability may allow remote attackers to send requests that trigger repeated parsing of malformed XML and may lead to NGINX worker termination or denial of service. 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.