Logout bypass via alternate JWT spelling

{
  "id": "f96251dde62c51514b4b321a63dbbd0f4c6f0f0c28213f4fb01886011aa47afe",
  "url": "https://osv.dev/vulnerability/CVE-2026-78426",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Logout bypass via alternate JWT spelling",
    "summary": "The NeuVector JWT verifier accepts noncanonical Base64URL encodings of the same RSA signature field. An attacker holding a valid JWT that has not expired, but was logged out of NeuVector, can continue using the non-expired token with equivalent spelling of the RSA signature field until the token validity expires.",
    "evidence": "osv:CVE-2026-78426",
    "products": [],
    "severity": "low",
    "structured": {
      "id": "CVE-2026-78426",
      "aliases": [
        "CVE-2026-78426",
        "GHSA-wcx5-mq6c-c54j"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:H/AT:N/PR:L/UI:A/VC:L/VI:L/VA:N/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/neuvector/neuvector",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "e457da1608de9231df7b82731e4d8cad9e910863"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "5.6.2"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "ChangesAt"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v5.6.2-rc4",
            "v5.6.2-rc3",
            "v5.6.2-rc2",
            "v5.6.1-rc4",
            "v5.6.1-rc3",
            "v5.6.1",
            "v5.6.0-rc4",
            "v5.6.0",
            "v5.6.0-rc3",
            "v5.6.0-rc1",
            "controller/k8sapi/v1.0.0",
            "v5.4.9",
            "v5.5.1-rc4",
            "v5.5.1-rc3",
            "v5.5.1-rc2",
            "v5.5.0-rc4",
            "v5.5.0-rc3",
            "v5.5.0",
            "v5.5.0-rc2",
            "v5.5.0-rc1",
            "v5.4.9-rc3",
            "v5.4.9-rc2",
            "v5.4.9-rc1",
            "v5.4.8",
            "v5.4.8-rc3",
            "v5.4.8-rc2",
            "v5.4.8-rc1",
            "v5.4.7-rc2",
            "v5.4.7-rc1",
            "v5.4.6-rc1",
            "v5.4.5-rc2",
            "v5.4.5",
            "v5.4.4-rc2",
            "v5.4.4",
            "v5.4.5-rc1",
            "v5.4.4-rc1",
            "v5.4.3-rc2",
            "v5.4.3-rc1",
            "v5.4.1-alpha",
            "v5.4.0-b3",
            "v5.4.0-b2-alpine",
            "v5.4.0-b2",
            "v5.4.0-b1-bci",
            "v5.4.0-b1",
            "voc415.1",
            "v5.3.3-b1",
            "v5.3.1-b1",
            "v5.3.0-b3",
            "v5.3.0-b2",
            "v5.3.0-b1",
            "v5.2.2-b2",
            "v5.2.2-b1",
            "v8040.1",
            "vlogvul.1",
            "v5.2.0-s1",
            "v5.2.0",
            "v5.2.0-b1",
            "vnsprune.1",
            "v5.1.1",
            "v5.1.1-b1",
            "v5.1.0-rc1",
            "vcilium.1",
            "veg.1",
            "v5.0.0-b2",
            "v5.0.0-b1",
            "v5.0.0-preview.3",
            "v5.0.0-preview.2",
            "v5.0.0-preview.1"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-78426.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:38.732682151Z",
      "provider": "osv",
      "references": [
        "https://github.com/neuvector/neuvector/security/",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/78xxx/CVE-2026-78426.json",
        "https://github.com/neuvector/neuvector/security/advisories/GHSA-wcx5-mq6c-c54j",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-78426",
        "https://bugzilla.suse.com/show_bug.cgi?id=CVE-2026-78426"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-863"
        ],
        "cna_assigner": "suse",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/78xxx/CVE-2026-78426.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-78426",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 506211,
  "published_at": "2026-09-17T09:28:19.683+00:00"
}