CVE-2026-55723: When NGINX Ingress Controller is configured with Custom Resource Definitions (CRDs) or Ingress annotations, an injection vulnerability exists in the configuration generator of NGIN
When NGINX Ingress Controller is configured with Custom Resource Definitions (CRDs) or Ingress annotations, an injection vulnerability exists in the configuration generator of NGINX Ingress Controller. Multiple user-controllable fields are written into the generated NGINX configuration without sanitization. An authenticated attacker with permission to create or modify these CRDs or annotations may craft values that inject arbitrary NGINX configuration directives.
Impact:
An authenticated attacker granted write access to NGINX Ingress Controller CRDs or Ingress annotations through the Kubernetes API may be able to inject arbitrary NGINX configuration directives, create or delete files, or disable services. There is no data plane exposure; this is a control plane issue only.
Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
Details
Original advisory: https://nvd.nist.gov/vuln/detail/CVE-2026-55723
Exploitation outlook
EPSS (FIRST.org) estimates each CVE’s probability of exploitation in the next 30 days — here is the CSIRTS.com read on those numbers.
- Low exploitation riskCVE-2026-557230.29% 30-day exploitation probability — currently an unlikely target, but scores change as exploit code circulates. Riskier than 22% of all scored CVEs.
Referenced CVEs
| CVE | CSIRTS overview | External |
|---|---|---|
| CVE-2026-55723 | coverage & exploitation status | NVD · CVE.org |
Same CVEs, other sources
How other CERTs, PSIRTs and databases cover the vulnerabilities in this advisory.
- unknownMultiple vulnerabilities in F5 products (July 16, 2026)cert-fr-avis
Recent advisories for When NGINX Ingress
A cluster of recent advisories against the same product widens the attack surface — attackers routinely chain freshly published CVEs on one product, so review these together.
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