Capsule: hostnameRegexHandler.OnUpdate validates stale (old) Tenant regex, allowing invalid AllowedHostnames regex to bypass webhook validation

{
  "id": "acf269e9cec3aa29dd1a2f275bca88f6df6aa06ff2f11d904af8f1ec7f6f32b8",
  "url": "https://osv.dev/vulnerability/CVE-2026-61795",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Capsule: hostnameRegexHandler.OnUpdate validates stale (old) Tenant regex, allowing invalid AllowedHostnames regex to bypass webhook validation",
    "summary": "Capsule is a multi-tenancy and policy-based framework for Kubernetes. From 0.13.0 until 0.13.7, hostnameRegexHandler.OnUpdate in internal/webhook/tenant/validation/hostname_regex.go reverses the new and old Tenant parameters and validates the previous AllowedHostnames.Regex instead of the submitted value. A cluster administrator can therefore store a malformed AllowedHostnames.Regex after the webhook accepts the update based on stale valid state. Subsequent Ingress creation or update reaches validate_hostnames.go, which evaluates the malformed pattern, ignores the regular-expression error, and treats every hostname as unmatched, blocking Ingress operations for the affected tenant until an administrator repairs the Tenant configuration. This issue is fixed in version 0.13.7.",
    "evidence": "osv:CVE-2026-61795",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-61795",
      "aliases": [
        "CVE-2026-61795",
        "GHSA-f94q-w3w8-cj67",
        "GO-2026-6519"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:H/UI:N/S:C/C:N/I:N/A:H"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/projectcapsule/capsule",
              "type": "GIT",
              "events": [
                {
                  "introduced": "c6e109ca46ed7de3a0f371df75e8abc993413a64"
                },
                {
                  "fixed": "8d89d6865df6f41c7faa22fc9e807a57b01bfd0e"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0.13.0"
                      },
                      {
                        "fixed": "0.13.7"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8d89d6865df6f41c7faa22fc9e807a57b01bfd0e"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "8d89d6865df6f41c7faa22fc9e807a57b01bfd0e"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v0.13.7"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "0.13.7"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v0.13.6",
            "v0.13.5",
            "v0.13.4",
            "v0.13.3",
            "v0.13.2",
            "v0.13.1",
            "v0.13.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-61795.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:32.446493834Z",
      "provider": "osv",
      "references": [
        "https://github.com/projectcapsule/capsule/releases/tag/v0.13.7",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61795.json",
        "https://github.com/projectcapsule/capsule/security/advisories/GHSA-f94q-w3w8-cj67",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-61795",
        "https://github.com/projectcapsule/capsule/commit/8d89d6865df6f41c7faa22fc9e807a57b01bfd0e",
        "https://github.com/projectcapsule/capsule/pull/1983"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-697"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/61xxx/CVE-2026-61795.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-61795",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 499560,
  "published_at": "2026-09-18T16:31:42.182+00:00"
}