CVE-2026-91184Network attack vectorHinoki check available

Cross-tenant disclosure via unescaped authentication realms

Published Oct 14, 2026 · Updated Oct 14, 2026

Realm injection in F5 Networks NGINX Gateway Fabric allows remote authenticated users to read other tenants' secrets via crafted filters. The configuration generator copies AuthenticationFilter spec.basic.realm and spec.jwt.realm into nginx.conf without escaping or validation, allowing injected directives. Exploitation requires permission to configure a filter attached to an HTTPRoute or GRPCRoute on a shared Gateway; consequences include access to mounted secrets and route hijacking, not an unauthenticated data-plane trigger.

CVSS severityUnavailable
Unscored
EPSS probability0.48%
Next 30 days · Oct 19, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkAvailable
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Summary

What happened

Realm injection in F5 Networks NGINX Gateway Fabric allows remote authenticated users to read other tenants' secrets via crafted filters. The configuration generator copies AuthenticationFilter spec.basic.realm and spec.jwt.realm into nginx.conf without escaping or validation, allowing injected directives. Exploitation requires permission to configure a filter attached to an HTTPRoute or GRPCRoute on a shared Gateway; consequences include access to mounted secrets and route hijacking, not an unauthenticated data-plane trigger.

The record

CVE
CVE-2026-91184
Published
Oct 14, 2026
Updated
Oct 14, 2026
Vendor
F5 Networks
Product
NGINX Gateway Fabric
Classifications
T1552.001
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Oct 14, 2026CVE publishedPublication date reported by the CVE source.
  2. Oct 14, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=2.4.0 <2.8.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

F5 Networks · NGINX Gateway Fabricversion=2.4.0 <2.8.0

Published CVSS scores

No CVSS assessment is available in this record.

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

Activity data is delayed. The latest report is Sep 28, 2026.

Daily unique IPsNo honeypot observations are available for this CVE in the selected window.

No observations available

Sep 22, 2026Sep 28, 2026
Latest reporting daySep 28, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitUnconfirmed

Weakness, pattern, technique

T1552.001Unsecured Credentials: Credentials In Files

Public exploit references

No public exploit references are available in this record.

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

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Your stack

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