Edgeless Systems Contrast through 1.20.0 Denial of Service via ciphertextContainer

{
  "id": "79416bdf20dbd8f55238a8d598e0c46059b084a1c9d1c31001fc6b7fabeaf302",
  "url": "https://osv.dev/vulnerability/CVE-2026-100836",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Edgeless Systems Contrast through 1.20.0 Denial of Service via ciphertextContainer",
    "summary": "Contrast through 1.20.0 contains a panic vulnerability in the transit-engine endpoint's ciphertextContainer.UnmarshalJSON function that fails to validate decoded ciphertext length before slicing. An authenticated workload with a valid mesh certificate can trigger a runtime panic by submitting a short base64-encoded ciphertext, causing log spam and request failures without crashing the process.",
    "evidence": "osv:CVE-2026-100836",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-100836",
      "aliases": [
        "CVE-2026-100836",
        "GHSA-3ccm-4qq2-5wrp",
        "GO-2026-5864"
      ],
      "metrics": [
        {
          "type": "CVSS_V4",
          "score": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:L/SC:N/SI:N/SA:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/edgelesssys/contrast",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "8f32af3e8d3ed928ea3e85079fd7ec621f9e1dca"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.20.0"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StandardRange"
                  },
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.20.0"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.20.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-100836.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:49.440277085Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100836.json",
        "https://github.com/edgelesssys/contrast/security/advisories/GHSA-3ccm-4qq2-5wrp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-100836",
        "https://www.vulncheck.com/advisories/edgeless-systems-contrast-through-1.20.0-denial-of-service-via-ciphertextcontainer"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-129"
        ],
        "cna_assigner": "VulnCheck",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/100xxx/CVE-2026-100836.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-100836",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 517922,
  "published_at": "2026-09-27T01:29:58.07+00:00"
}