Vulnerability-Lookup

FKIE_CVE-2026-91184

Vulnerability from fkie_nvd - Published: 2026-10-14 15:17 - Updated: 2026-10-15 04:18

Severity

8.8 (High) - CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H

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.

References

	URL	Tags
	f5sirt@f5.com	https://my.f5.com/manage/s/article/K000162609

Impacted products

	Vendor	Product	Version

JSON

To clipboard

{
  "affected": [
    {
      "affectedData": [
        {
          "defaultStatus": "unknown",
          "modules": [
            "NGF"
          ],
          "product": "NGINX Gateway Fabric",
          "vendor": "F5",
          "versions": [
            {
              "lessThan": "2.8.0",
              "status": "affected",
              "version": "2.4.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "source": "f5sirt@f5.com"
    }
  ],
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "Description\n\nNGINX Gateway Fabric\u00a0has 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 \"\u003crealm\u003e\";. 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\u0027s data-plane config.\u00a0\n\nImpact\n\nA remote authenticated attacker can send crafted requests to configure NGINX Gateway Fabric\u00a0AuthenticationFilter CRD and\u00a0may be able to read every co-located tenant\u0027s mounted secrets, SSRF via proxy_pass, reading the pod ServiceAccount token, or hijacking other tenants\u0027 routes.\u00a0There is no data plane exposure; this is a control plane issue only.\n\n\n\n\n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
    }
  ],
  "id": "CVE-2026-91184",
  "lastModified": "2026-10-15T04:18:29.000",
  "metrics": {
    "cvssMetricV31": [
      {
        "cvssData": {
          "attackComplexity": "LOW",
          "attackVector": "NETWORK",
          "availabilityImpact": "HIGH",
          "baseScore": 8.8,
          "baseSeverity": "HIGH",
          "confidentialityImpact": "HIGH",
          "integrityImpact": "HIGH",
          "privilegesRequired": "LOW",
          "scope": "UNCHANGED",
          "userInteraction": "NONE",
          "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
          "version": "3.1"
        },
        "exploitabilityScore": 2.8,
        "impactScore": 5.9,
        "source": "f5sirt@f5.com",
        "type": "Secondary"
      }
    ],
    "cvssMetricV40": [
      {
        "cvssData": {
          "Automatable": "NOT_DEFINED",
          "Recovery": "NOT_DEFINED",
          "Safety": "NOT_DEFINED",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "attackVector": "NETWORK",
          "availabilityRequirement": "NOT_DEFINED",
          "baseScore": 8.7,
          "baseSeverity": "HIGH",
          "confidentialityRequirement": "NOT_DEFINED",
          "exploitMaturity": "NOT_DEFINED",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "privilegesRequired": "LOW",
          "providerUrgency": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "subConfidentialityImpact": "NONE",
          "subIntegrityImpact": "NONE",
          "userInteraction": "NONE",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "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/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",
          "version": "4.0",
          "vulnAvailabilityImpact": "HIGH",
          "vulnConfidentialityImpact": "HIGH",
          "vulnIntegrityImpact": "HIGH",
          "vulnerabilityResponseEffort": "NOT_DEFINED"
        },
        "source": "f5sirt@f5.com",
        "type": "Secondary"
      }
    ],
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-91184",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "total"
            }
          ],
          "role": "CISA Coordinator",
          "timestamp": "2026-10-14T00:00:00+00:00",
          "version": "2.0.3"
        }
      }
    ]
  },
  "published": "2026-10-14T15:17:26.420",
  "references": [
    {
      "source": "f5sirt@f5.com",
      "url": "https://my.f5.com/manage/s/article/K000162609"
    }
  ],
  "sourceIdentifier": "f5sirt@f5.com",
  "vulnStatus": "Awaiting Analysis",
  "weaknesses": [
    {
      "description": [
        {
          "lang": "en",
          "value": "CWE-76"
        }
      ],
      "source": "f5sirt@f5.com",
      "type": "Secondary"
    }
  ]
}

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

Vulnerability from cvelistv5 – Published: 2026-10-14 14:40 – Updated: 2026-10-15 03:57

Title

NGINX Gateway Fabric vulnerability

Summary

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

CWE-76

Assigner

f5 CNA under the mitre root

CNA scorecard B 84/100 over 87 records in the last 180 days details

References

1 reference

URL	Tags
https://my.f5.com/manage/s/article/K000162609	vendor-advisory

Impacted products

1 product

Vendor	Product	Version
F5	NGINX Gateway Fabric	Affected: 2.4.0 , < 2.8.0 (custom)

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

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-91184",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "no"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-10-14T00:00:00+00:00",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-10-15T03:57:01.486Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "defaultStatus": "unknown",
          "modules": [
            "NGF"
          ],
          "product": "NGINX Gateway Fabric",
          "vendor": "F5",
          "versions": [
            {
              "lessThan": "2.8.0",
              "status": "affected",
              "version": "2.4.0",
              "versionType": "custom"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "F5 acknowledges apvxlab (AppViewX security research) for bringing this issue to our attention and following the highest standards of coordinated disclosure."
        }
      ],
      "datePublic": "2023-01-01T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "Description\u003cbr\u003e\u003cbr\u003eNGINX Gateway Fabric\u0026nbsp;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 \"\u0026lt;realm\u0026gt;\";. 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\u0027s data-plane config.\u0026nbsp;\u003cbr\u003e\u003cbr\u003eImpact\u003cbr\u003e\u003cbr\u003eA remote authenticated attacker can send crafted requests to configure NGINX Gateway Fabric\u0026nbsp;AuthenticationFilter CRD and\u0026nbsp;may be able to read every co-located tenant\u0027s mounted secrets, SSRF via proxy_pass, reading the pod ServiceAccount token, or hijacking other tenants\u0027 routes.\u0026nbsp;\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eThere is no data plane exposure; this is a control plane issue only.\u003c/span\u003e\n\n\u003cbr\u003e\u003cbr\u003e\n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
            }
          ],
          "value": "Description\n\nNGINX Gateway Fabric\u00a0has 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 \"\u003crealm\u003e\";. 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\u0027s data-plane config.\u00a0\n\nImpact\n\nA remote authenticated attacker can send crafted requests to configure NGINX Gateway Fabric\u00a0AuthenticationFilter CRD and\u00a0may be able to read every co-located tenant\u0027s mounted secrets, SSRF via proxy_pass, reading the pod ServiceAccount token, or hijacking other tenants\u0027 routes.\u00a0There is no data plane exposure; this is a control plane issue only.\n\n\n\n\n\n\nNote: Software versions which have reached End of Technical Support (EoTS) are not evaluated."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-3",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-3 Using Leading \u0027Ghost\u0027 Character Sequences to Bypass Input Filters"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "HIGH",
            "baseScore": 8.8,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "HIGH",
            "privilegesRequired": "LOW",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 8.7,
            "baseSeverity": "HIGH",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "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",
            "version": "4.0",
            "vulnAvailabilityImpact": "HIGH",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-76",
              "description": "CWE-76",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-14T14:40:27.849Z",
        "orgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab",
        "shortName": "f5"
      },
      "references": [
        {
          "tags": [
            "vendor-advisory"
          ],
          "url": "https://my.f5.com/manage/s/article/K000162609"
        }
      ],
      "source": {
        "discovery": "EXTERNAL"
      },
      "title": "NGINX Gateway Fabric vulnerability",
      "workarounds": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003e\n\n\u003cdiv\u003e\u003cp\u003eAs this attack is conducted by authenticated users with Kubernetes Role-based Access Control (RBAC) write access to AuthenticationFilter\u0026nbsp;\u003cspan style=\"background-color: rgb(255, 255, 255);\"\u003eCRD\u003c/span\u003e\u0026nbsp;and Secrets, the only complete mitigation is to restrict that access to fully trusted administrators only.\u003c/p\u003e\u003c/div\u003e\u003c/span\u003e"
            }
          ],
          "value": "As this attack is conducted by authenticated users with Kubernetes Role-based Access Control (RBAC) write access to AuthenticationFilter\u00a0CRD\u00a0and Secrets, the only complete mitigation is to restrict that access to fully trusted administrators only."
        }
      ],
      "x_generator": {
        "engine": "F5 SIRTBot v1.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "9dacffd4-cb11-413f-8451-fbbfd4ddc0ab",
    "assignerShortName": "f5",
    "cveId": "CVE-2026-91184",
    "datePublished": "2026-10-14T14:40:27.849Z",
    "dateReserved": "2026-09-30T21:56:14.612Z",
    "dateUpdated": "2026-10-15T03:57:01.486Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

Sightings and recorded dates, grouped by day · UTC

Order JSON

Publication & reservation Sightings KEV catalogs Other timestamps

Loading timeline…

The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

Action not permitted