Common Weakness Enumeration
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CWE-76
Improper Neutralization of Equivalent Special Elements
The product correctly neutralizes certain special elements, but it improperly neutralizes equivalent special elements.
CVE-2026-55723 (GCVE-0-2026-55723)
Vulnerability from cvelistv5 – Published: 2026-07-15 14:33 – Updated: 2026-07-16 03:55
VLAI
EPSS
VEX
Title
NGINX Ingress Controller vulnerability
Summary
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.
Severity
SSVC
Exploitation: none
Automatable: no
Technical Impact: total
CISA Coordinator (v2.0.3)
CWE
- CWE-76 - Improper Neutralization of Equivalent Special Elements
Assigner
References
1 reference
| URL | Tags |
|---|---|
| https://my.f5.com/manage/s/article/K000161800 | vendor-advisorypatch |
Impacted products
1 product
| Vendor | Product | Version | |
|---|---|---|---|
| F5 | NGINX Ingress Controller |
Affected:
5.0.0 , < 5.5.2
(custom)
Affected: 2026-lts-r1 , < 2026-lts-r3 (custom) |
Date Public
2026-07-15 14:00
Credits
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Mitigation
Phase: Requirements
Description:
- Programming languages and supporting technologies might be chosen which are not subject to these issues.
Mitigation
Phase: Implementation
Description:
- Utilize an appropriate mix of allowlist and denylist parsing to filter equivalent special element syntax from all input.
No CAPEC attack patterns related to this CWE.