CVE-2026-55723
Last modified
CVE-2026-55723 is a high-severity vulnerability rated 8.7/10 on the CVSS scale. 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. EPSS estimates a 0.29% chance of exploitation in the next 30 days.
Description
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.
Metrics
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:L
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:L/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness Enumeration
Affected Software
| Vendor | Product | Versions |
|---|---|---|
| F5 | Nginx Ingress Controller | >= 3.6.0, <= 3.7.2 |
| F5 | Nginx Ingress Controller | >= 4.0.0, <= 4.0.1 |
| F5 | Nginx Ingress Controller | >= 5.0.0, < 5.5.2 |
References
- https://my.f5.com/manage/s/article/K000161800Mitigation, Vendor Advisory
Timeline
- Published
- Last Modified
- Status
- Analyzed
Frequently Asked Questions
What is CVE-2026-55723?
How severe is CVE-2026-55723?
How do I fix CVE-2026-55723?
How Strix Helps
- How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
- Autonomous PentestingAI agents that find and validate exploitable vulnerabilities like this one across your applications.
- PR ReviewsPentest every pull request so vulnerable code is caught before it ships to production.
- AI Penetration TestingHow AI-driven penetration testing continuously covers your attack surface.
Related CVEs from 2026
- CVE-2026-55707In OpenStack Neutron before 28.0.2, the subnetpool onboardin…7.1
- CVE-2026-55708In NLnet Labs Unbound 1.6.0 up to and including 1.25.1, the …3.1
- CVE-2026-5571A vulnerability was identified in Technostrobe HI-LED-WR120-…7.5
- CVE-2026-55717In NLnet Labs Unbound 1.10.0 up to and including 1.25.1, whe…5.9
- CVE-2026-5572A security flaw has been discovered in Technostrobe HI-LED-W…4.3
- CVE-2026-55721Storage Concentrator (SC & SCVM) is vulnerable to SQL inject…9.3
- CVE-2026-55726The Azure Blob Storage container used for Gardyn device logs…6.9
- CVE-2026-55727A flaw in the authentication mechanism for video stream requ…7.5
- CVE-2026-55728Stack-based Buffer Overflow (CWE-121) in `/usr/bin/ltsudo` `…3.8
- CVE-2026-55729Exposure of Sensitive Information (CWE-200) in LWEB802 brows…7.7
- CVE-2026-5573A weakness has been identified in Technostrobe HI-LED-WR120-…9.8
- CVE-2026-55730Reflected Cross-Site Scripting (CWE-79) in LWEB802 in Loytec…8.7
Are you affected by CVE-2026-55723?
Run a free Strix scan to check your systems for this vulnerability.
Scan your code nowSource: NVD / NIST