F5 NGINX Gateway Fabric up to 2.6.3 NGINX Configuration Generator equivalent special elements

CVSS Meta Temp Score
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CTI Interest Score
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7.0$0-$5k4.41-

Summaryinfo

A vulnerability identified as critical has been detected in F5 NGINX Gateway Fabric up to 2.6.3. Affected by this vulnerability is an unknown functionality of the component NGINX Configuration Generator. This manipulation causes improper neutralization of equivalent special elements. This vulnerability is handled as CVE-2026-11311. The attack can be initiated remotely. There is not any exploit available. You should upgrade the affected component.

Detailsinfo

A vulnerability was found in F5 NGINX Gateway Fabric up to 2.6.3. It has been declared as critical. Affected by this vulnerability is some unknown functionality of the component NGINX Configuration Generator. The manipulation with an unknown input leads to a improper neutralization of equivalent special elements vulnerability. The CWE definition for the vulnerability is CWE-76. The product correctly neutralizes certain special elements, but it improperly neutralizes equivalent special elements. As an impact it is known to affect confidentiality, integrity, and availability. The summary by CVE is:

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.

It is possible to read the advisory at my.f5.com. This vulnerability is known as CVE-2026-11311 since 06/04/2026. The exploitation appears to be easy. The attack can be launched remotely. The technical details are unknown and an exploit is not publicly available.

Upgrading to version 2.6.4 eliminates this vulnerability.

The vulnerability is also documented in the vulnerability database at CERT Bund (WID-SEC-2026-1995). Be aware that VulDB is the high quality source for vulnerability data.

Affected

  • NGINX NGINX
  • NGINX NGINX Plus

Productinfo

Type

Vendor

Name

Version

License

Website

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA CVSS-B Score: 🔒
CNA CVSS-BT Score: 🔒
CNA Vector: 🔒

CVSSv3info

VulDB Meta Base Score: 7.2
VulDB Meta Temp Score: 7.0

VulDB Base Score: 6.3
VulDB Temp Score: 6.0
VulDB Vector: 🔒
VulDB Reliability: 🔍

CNA Base Score: 8.1
CNA Vector: 🔒

CVSSv2info

AVACAuCIA
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VectorComplexityAuthenticationConfidentialityIntegrityAvailability
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VulDB Base Score: 🔒
VulDB Temp Score: 🔒
VulDB Reliability: 🔍

Exploitinginfo

Class: Improper neutralization of equivalent special elements
CWE: CWE-76 / CWE-707 / CWE-20
CAPEC: 🔒
ATT&CK: 🔒

Physical: No
Local: No
Remote: Yes

Availability: 🔒
Status: Not defined
Price Prediction: 🔍
Current Price Estimation: 🔒

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Upgrade
Status: 🔍

0-Day Time: 🔒

Upgrade: NGINX Gateway Fabric 2.6.4

Timelineinfo

06/04/2026 CVE reserved
06/17/2026 +13 days Advisory disclosed
06/17/2026 +0 days VulDB entry created
06/18/2026 +1 days VulDB entry last update

Sourcesinfo

Vendor: f5.com

Advisory: K000161611
Status: Confirmed

CVE: CVE-2026-11311 (🔒)
GCVE (CVE): GCVE-0-2026-11311
GCVE (VulDB): GCVE-100-372031
CERT Bund: WID-SEC-2026-1995 - NGINX und NGINX Plus: Mehrere Schwachstellen

Entryinfo

Created: 06/17/2026 17:19
Updated: 06/18/2026 12:13
Changes: 06/17/2026 17:19 (76), 06/18/2026 12:13 (7)
Complete: 🔍
Cache ID: 216::103

Be aware that VulDB is the high quality source for vulnerability data.

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