rekor — security advisory

{
  "id": "9f03bd0155d78a6b10768acf7f4cc3dc0e7ae30578f9760468c65c999d1111eb",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-23831",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-23831",
    "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:UBUNTU-CVE-2026-23831",
    "products": [
      {
        "name": {
          "value": "rekor",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.3.7-1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "1.3.9-1",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "rekor",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.5.0-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.5.2-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.5.3-1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "1.5.3-2",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "rekor",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "1.3.9-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "1.5.0-1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "1.5.0-1ubuntu0.26.04.1~esm1",
            "evidence": "/affected/2/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-23831",
      "aliases": [
        "UBUNTU-CVE-2026-23831"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "rekor",
            "purl": "pkg:deb/ubuntu/rekor?arch=source&distro=questing",
            "ecosystem": "Ubuntu:25.10"
          },
          "versions": [
            "1.3.7-1",
            "1.3.9-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-23831.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "golang-github-sigstore-rekor-dev",
                "binary_version": "1.3.9-1"
              },
              {
                "binary_name": "rekor",
                "binary_version": "1.3.9-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "rekor",
            "purl": "pkg:deb/ubuntu/rekor?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "1.5.0-1",
            "1.5.2-1",
            "1.5.3-1",
            "1.5.3-2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-23831.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "golang-github-sigstore-rekor-dev",
                "binary_version": "1.5.3-2"
              },
              {
                "binary_name": "rekor",
                "binary_version": "1.5.3-2"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "rekor",
            "purl": "pkg:deb/ubuntu/rekor?arch=source&distro=esm-apps%2Fresolute",
            "ecosystem": "Ubuntu:Pro:26.04:LTS"
          },
          "versions": [
            "1.3.9-1",
            "1.5.0-1",
            "1.5.0-1ubuntu0.26.04.1~esm1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-23831.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "golang-github-sigstore-rekor-dev",
                "binary_version": "1.5.0-1ubuntu0.26.04.1~esm1"
              },
              {
                "binary_name": "rekor",
                "binary_version": "1.5.0-1ubuntu0.26.04.1~esm1"
              }
            ]
          }
        }
      ],
      "modified": "2026-10-17T12:59:56.380326368Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-23831"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-23831",
        "https://www.cve.org/CVERecord?id=CVE-2026-23831",
        "https://github.com/sigstore/rekor/security/advisories/GHSA-273p-m2cw-6833",
        "https://github.com/sigstore/rekor/commit/39bae3d192bce48ef4ef2cbd1788fb5770fee8cd",
        "https://github.com/sigstore/rekor/releases/tag/v1.5.0"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-23831",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 360001,
  "published_at": "2026-01-22T22:16:00+00:00"
}