Kestra Vulnerable to Stored Cross-Site Scripting via Flow YAML Fields

{
  "id": "50e4640872377b1087772b17f7af608fb6a57397dab7f013d52ae67916577a8b",
  "url": "https://osv.dev/vulnerability/CVE-2026-33664",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Kestra Vulnerable to Stored Cross-Site Scripting via Flow YAML Fields",
    "summary": "Kestra is an open-source, event-driven orchestration platform Versions up to and including 1.3.3 render user-supplied flow YAML metadata fields — description, inputs[].displayName, inputs[].description — through the Markdown.vue component instantiated with html: true. The resulting HTML is injected into the DOM via Vue's v-html without any sanitization. This allows a flow author to embed arbitrary JavaScript that executes in the browser of any user who views or interacts with the flow. This is distinct from GHSA-r36c-83hm-pc8j / CVE-2026-29082, which covers only FilePreview.vue rendering .md files from execution outputs. The present finding affects different components, different data sources, and requires significantly less user interaction (zero-click for input.displayName). As of time of publication, it is unclear if a patch is available.",
    "evidence": "osv:CVE-2026-33664",
    "products": [],
    "severity": "high",
    "structured": {
      "id": "CVE-2026-33664",
      "aliases": [
        "CVE-2026-33664",
        "GHSA-v2mc-8q95-g7hp"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/kestra-io/kestra",
              "type": "GIT",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "last_affected": "63603539415a4b29f65a75cec8e733f6424005ac"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.3.3"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "cpe": "cpe:2.3:a:kestra:kestra:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "0"
                      },
                      {
                        "last_affected": "1.3.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v1.3.3",
            "v1.3.2",
            "v1.3.1",
            "v1.3.0",
            "v1.3.0-rc1",
            "v1.3.0-rc0",
            "v0.0.1234",
            "v0.19.0",
            "v0.9.1",
            "v0.9.0",
            "v0.8.1",
            "v0.8.0",
            "v0.7.1",
            "v0.7.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-33664.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:30.297271977Z",
      "provider": "osv",
      "references": [
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33664.json",
        "https://github.com/kestra-io/kestra/security/advisories/GHSA-v2mc-8q95-g7hp",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-33664"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-79"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33664.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-33664",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 497144,
  "published_at": "2026-03-26T21:13:12.467+00:00"
}