Rekor COSE v0.0.1 Canonicalize crashes when passed empty Message

{
  "id": "32ce1f4c35509586ec5bbcd355ec732dbbbfaf2ed3cc1dbcda57647c25ab35cd",
  "url": "https://osv.dev/vulnerability/CVE-2026-23831",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Rekor COSE v0.0.1 Canonicalize crashes when passed empty Message",
    "summary": "Rekor is a software supply chain transparency log. In versions 1.4.3 and below, the entry implementation can panic on attacker-controlled input when canonicalizing a proposed entry with an empty spec.message, causing nil Pointer Dereference. Function validate() returns nil (success) when message is empty, leaving sign1Msg uninitialized, and Canonicalize() later dereferences v.sign1Msg.Payload. A malformed proposed entry of the cose/v0.0.1 type can cause a panic on a thread within the Rekor process. The thread is recovered so the client receives a 500 error message and service still continues, so the availability impact of this is minimal. This issue has been fixed in version 1.5.0.",
    "evidence": "osv:CVE-2026-23831",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-23831",
      "aliases": [
        "CVE-2026-23831",
        "GHSA-273p-m2cw-6833",
        "GO-2026-4354"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/sigstore/rekor",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "fe9717fd6ee4cfecedc30e5fd64c9872bc2ac61c"
                },
                {
                  "fixed": "39bae3d192bce48ef4ef2cbd1788fb5770fee8cd"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:linuxfoundation:rekor:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "fixed": "1.5.0"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "range": [
                      {
                        "fixed": "39bae3d192bce48ef4ef2cbd1788fb5770fee8cd"
                      }
                    ],
                    "source": "REFERENCES_COMMIT"
                  },
                  {
                    "range": [
                      {
                        "fixed": "fe9717fd6ee4cfecedc30e5fd64c9872bc2ac61c"
                      }
                    ],
                    "source": "REFERENCES_TAG",
                    "original_tag": "v1.5.0"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.4.3",
            "v1.4.2",
            "v1.4.1",
            "v1.4.0",
            "v1.3.10",
            "v1.3.9",
            "v1.3.8",
            "v1.3.7",
            "v1.3.6",
            "v1.3.5",
            "v1.3.4",
            "v1.3.3",
            "v1.3.2",
            "v1.3.1",
            "v1.3.0",
            "v1.2.2",
            "v1.2.1",
            "v1.2.0",
            "v1.1.1",
            "v1.1.0",
            "v1.0.0",
            "v1.0.0-rc.1",
            "v1.0-rc",
            "v0.12.1",
            "v0.12.0",
            "v0.11.0",
            "v0.10.0",
            "v0.9.1",
            "v0.9.0",
            "v0.8.2",
            "v0.8.1",
            "v0.8.0",
            "v0.7.0",
            "v0.6.0",
            "v0.5.0",
            "v0.4.0",
            "v0.3.0",
            "v0.2.0",
            "v0.1.1",
            "v0.1.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-23831.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:46.433232582Z",
      "provider": "osv",
      "references": [
        "https://github.com/sigstore/rekor/releases/tag/v1.5.0",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23831.json",
        "https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-23831",
        "https://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-476"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/23xxx/CVE-2026-23831.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-23831",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 514548,
  "published_at": "2026-01-22T21:26:22.183+00:00"
}