Vulnerability-Lookup

GHSA-WV26-88M5-6H59

Vulnerability from github – Published: 2026-05-05 18:37 – Updated: 2026-05-13 14:18

Summary

External Secrets Operator has Namespace Isolation Bypass in CAProvider ConfigMap Resolution for SecretStore

Details

Impact

Namespaced SecretStore resources that used CAProvider with type ConfigMap could resolve CA material from another namespace when caProvider.namespace was set. This bypassed the namespace boundary enforced for SecretStore-backed references in providers that rely on the shared runtime CA resolver.

The accessible data is used as CA validation material, hence it is not directly exposed.

Impact: - Direct data exfiltration risk: low - Existence disclosure: an attacker can infer whether a target ConfigMap/key exists in another namespace. - Trust-boundary violation: a tenant can make its SecretStore consume CA material owned by another namespace.

Severity

5.3 (Medium)


                  
                    CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

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{
  "affected": [
    {
      "package": {
        "ecosystem": "Go",
        "name": "github.com/external-secrets/external-secrets"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "2.4.0"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-42875"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-285",
      "CWE-668"
    ],
    "github_reviewed": true,
    "github_reviewed_at": "2026-05-05T18:37:12Z",
    "nvd_published_at": "2026-05-11T20:25:44Z",
    "severity": "MODERATE"
  },
  "details": "### Impact\n\nNamespaced SecretStore resources that used CAProvider with type `ConfigMap` could resolve CA material from another namespace when `caProvider.namespace` was set. \nThis bypassed the namespace boundary enforced for SecretStore-backed references in providers that rely on the shared runtime CA resolver. \n\nThe accessible data is used as CA validation material, hence it is not directly exposed.\n\nImpact:\n- Direct data exfiltration risk: low\n- Existence disclosure: an attacker can infer whether a target ConfigMap/key exists in another namespace.\n- Trust-boundary violation: a tenant can make its SecretStore consume CA material owned by another namespace.",
  "id": "GHSA-wv26-88m5-6h59",
  "modified": "2026-05-13T14:18:52Z",
  "published": "2026-05-05T18:37:12Z",
  "references": [
    {
      "type": "WEB",
      "url": "https://github.com/external-secrets/external-secrets/security/advisories/GHSA-wv26-88m5-6h59"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-42875"
    },
    {
      "type": "PACKAGE",
      "url": "https://github.com/external-secrets/external-secrets"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
      "type": "CVSS_V4"
    }
  ],
  "summary": "External Secrets Operator has Namespace Isolation Bypass in CAProvider ConfigMap Resolution for SecretStore"
}

CVE-2026-42875 (GCVE-0-2026-42875)

Vulnerability from cvelistv5 – Published: 2026-05-11 18:56 – Updated: 2026-05-12 16:25

Title

External Secrets Operator: Namespace Isolation Bypass in CAProvider ConfigMap Resolution for SecretStore

Summary

External Secrets Operator reads information from a third-party service and automatically injects the values as Kubernetes Secrets. Prior to 2.4.0, Namespaced SecretStore resources that used CAProvider with type ConfigMap could resolve CA material from another namespace when caProvider.namespace was set. This bypassed the namespace boundary enforced for SecretStore-backed references in providers that rely on the shared runtime CA resolver. This vulnerability is fixed in 2.4.0.

Severity

5.3 (Medium)


                        
                          CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N

SSVC

Exploitation: none Automatable: yes Technical Impact: total

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-05-12 16:24 UTC

CWE

CWE-285 - Improper Authorization
CWE-668 - Exposure of Resource to Wrong Sphere

Assigner

GitHub_M mitre root Scorecard

References

1 reference

URL	Tags
https://github.com/external-secrets/external-secr…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
external-secrets	external-secrets	Affected: < 2.4.0

Show details on NVD website

JSON

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{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-42875",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "total"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-05-12T16:24:54.782478Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-05-12T16:25:13.165Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "external-secrets",
          "vendor": "external-secrets",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 2.4.0"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "External Secrets Operator reads information from a third-party service and automatically injects the values as Kubernetes Secrets. Prior to 2.4.0, Namespaced SecretStore resources that used CAProvider with type ConfigMap could resolve CA material from another namespace when caProvider.namespace was set. This bypassed the namespace boundary enforced for SecretStore-backed references in providers that rely on the shared runtime CA resolver. This vulnerability is fixed in 2.4.0."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "privilegesRequired": "LOW",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "LOW",
            "userInteraction": "NONE",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-285",
              "description": "CWE-285: Improper Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-668",
              "description": "CWE-668: Exposure of Resource to Wrong Sphere",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-05-11T18:56:34.097Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/external-secrets/external-secrets/security/advisories/GHSA-wv26-88m5-6h59",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/external-secrets/external-secrets/security/advisories/GHSA-wv26-88m5-6h59"
        }
      ],
      "source": {
        "advisory": "GHSA-wv26-88m5-6h59",
        "discovery": "UNKNOWN"
      },
      "title": "External Secrets Operator: Namespace Isolation Bypass in CAProvider ConfigMap Resolution for SecretStore"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-42875",
    "datePublished": "2026-05-11T18:56:34.097Z",
    "dateReserved": "2026-04-30T18:49:06.711Z",
    "dateUpdated": "2026-05-12T16:25:13.165Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

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Confirmed: The vulnerability has been validated from an analyst's perspective.
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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.

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.
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