CVE-2026-11311

MEDIUMCVSS 6.5/10EPSS 0.59%

Last modified

CVE-2026-11311 is a medium-severity vulnerability rated 6.5/10 on the CVSS scale. When NGINX Plus is configured as the data plane for NGINX Gateway Fabric, an injection vulnerability exists in the NGINX configuration generator component of NGINX Gateway Fabric. User-supplied string values from the NginxProxy Custom Resource Definition serverTokens field and the AuthenticationFilter Custom Resource Definition extraAuthArgs field are rendered directly into NGINX configuration templates without sanitization or escaping. EPSS estimates a 0.59% chance of exploitation in the next 30 days.

Description

When NGINX Plus is configured as the data plane for NGINX Gateway Fabric, an injection vulnerability exists in the NGINX configuration generator component of NGINX Gateway Fabric. User-supplied string values from the NginxProxy Custom Resource Definition serverTokens field and the AuthenticationFilter Custom Resource Definition extraAuthArgs field are rendered directly into NGINX configuration templates without sanitization or escaping. An authenticated attacker with permission to create or modify these Custom Resource Definitions may craft values that inject arbitrary NGINX configuration directives. This is a control plane issue; there is no data plane exposure from the vulnerability trigger itself. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.

Metrics

CVSS 3.1
6.5/10

CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:H/A:N

CVSS 4.0
8.6/10

CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:N/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 Probability
0.59%

43.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

Affected Software

VendorProductVersions
F5Nginx Gateway Fabric>= 2.5.0, < 2.6.4

References

Timeline

Published
Last Modified
Status
Analyzed

Frequently Asked Questions

What is CVE-2026-11311?
When NGINX Plus is configured as the data plane for NGINX Gateway Fabric, an injection vulnerability exists in the NGINX configuration generator component of NGINX Gateway Fabric. User-supplied string values from the NginxProxy Custom Resource Definition serverTokens field and the AuthenticationFilter Custom Resource Definition extraAuthArgs field are rendered directly into NGINX configuration templates without sanitization or escaping. An authenticated attacker with permission to create or modify these Custom Resource Definitions may craft values that inject arbitrary NGINX configuration directives. This is a control plane issue; there is no data plane exposure from the vulnerability trigger itself. Note: Software versions which have reached End of Technical Support (EoTS) are not evaluated.
How severe is CVE-2026-11311?
CVE-2026-11311 has a CVSS score of 6.5/10 (MEDIUM severity). The EPSS model estimates a 0.59% probability of exploitation in the next 30 days.
How do I fix CVE-2026-11311?
Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

How Strix Helps

Related CVEs from 2026

Are you affected by CVE-2026-11311?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST