CVE-2026-55723

HIGH
MEDIUM Priority: 0.04 BB Relevance: 68/100
Published: 2026-07-15 Modified: 2026-10-24 First seen: 2026-10-29 Status: active

Attack Surface

Network Low Complexity No Interaction Conf. Impact Integ. Impact

CVSS Vector Breakdown

AV: Network
AC: Low
PR: Low
UI: None
S: X
AT: None
VC: High
VI: High
VA: Low

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.

Weakness Classification (1)

Affected Software (3)

VendorProductVersion
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 & Advisories (1)

Bug Bounty Relevance

68 / 100
✓ Network accessible
✓ Low complexity
✓ No user interaction

CVSS Score

8.7 / 10.0 v4.0
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

EPSS — Exploitation Probability

0.51%
Raw Score 0.005090
Percentile 43.4%
Date 2026-10-29

EPSS Trend

2026-10-29
0.00509
2026-10-28
0.00509

Intelligence Sources

nvd ref →