CVE-2026-91184 (GCVE-0-2026-91184)

Vulnerability from cvelistv5 – Published: 2026-10-14 14:40 – Updated: 2026-10-15 03:57
VLAI
Title
NGINX Gateway Fabric vulnerability
Summary
Description NGINX Gateway Fabric has a vulnerability when it renders the spec.basic.realm (and spec.jwt.realm) field of a namespaced AuthenticationFilter verbatim, unescaped and unvalidated, into the shared data-plane nginx.conf as auth_basic "<realm>";. A namespaced authenticated attacker that configures AuthenticationFilter CRD to an HTTPRoute/GRPCRoute on a shared Gateway can craft a realm value that closes the quoted directive and the enclosing location {} block and injects arbitrary NGINX directives into that Gateway's data-plane config.  Impact A remote authenticated attacker can send crafted requests to configure NGINX Gateway Fabric AuthenticationFilter CRD and may be able to read every co-located tenant's mounted secrets, SSRF via proxy_pass, reading the pod ServiceAccount token, or hijacking other tenants' routes. 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.
Severity
8.8 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
SSVC
Exploitation: none Automatable: no Technical Impact: total
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-10-14 00:00 UTC
CWE
Assigner
f5 CNA under the mitre root
CNA scorecard B 84/100 over 87 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
F5 NGINX Gateway Fabric Affected: 2.4.0 , < 2.8.0 (custom)
guessed Create a notification for this product.
Date Public
2023-01-01 00:00
Credits
F5 acknowledges apvxlab (AppViewX security research) for bringing this issue to our attention and following the highest standards of coordinated disclosure.
Show details on NVD website
To clipboard 

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