{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "packageURL": "pkg:github/discourse/discourse",
          "product": "Discourse",
          "repo": "https://github.com/discourse/discourse",
          "vendor": "Discourse",
          "versions": [
            {
              "lessThan": "1.9.0.beta13",
              "status": "affected",
              "version": "1.9.0.beta2",
              "versionType": "custom"
            }
          ]
        }
      ],
      "cpeApplicability": [
        {
          "nodes": [
            {
              "cpeMatch": [
                {
                  "criteria": "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*",
                  "versionEndExcluding": "1.9.0.beta13",
                  "versionStartIncluding": "1.9.0.beta2",
                  "vulnerable": true
                }
              ],
              "negate": false,
              "operator": "OR"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "reporter",
          "value": "The Shadowserver Foundation"
        }
      ],
      "datePublic": "2017-10-09T00:00:00.000Z",
      "descriptions": [
        {
          "lang": "en",
          "value": "Discourse 1.9.0.beta2 before 1.9.0.beta13 contains a reflected cross-site scripting vulnerability that allows unauthenticated attackers to inject scripts through the email parameter of /email/unsubscribed. Attackers can craft GET requests with SVG onload payloads, which unsubscribed.html.erb renders unescaped via html_safe, executing JavaScript in victims\u0027 browsers. Exploitation evidence was first observed by the Shadowserver Foundation on 2023-10-19."
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "NONE",
            "attackVector": "NETWORK",
            "baseScore": 5.1,
            "baseSeverity": "MEDIUM",
            "exploitMaturity": "NOT_DEFINED",
            "privilegesRequired": "NONE",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "LOW",
            "subIntegrityImpact": "LOW",
            "userInteraction": "ACTIVE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:A/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "NONE",
            "vulnIntegrityImpact": "NONE",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        },
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 6.1,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "LOW",
            "privilegesRequired": "NONE",
            "scope": "CHANGED",
            "userInteraction": "REQUIRED",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
            "version": "3.1"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-10-22T10:57:24.711Z",
        "orgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
        "shortName": "VulnCheck"
      },
      "references": [
        {
          "name": "Fix Commit",
          "tags": [
            "patch"
          ],
          "url": "https://github.com/discourse/discourse/commit/a6f2533d38"
        },
        {
          "name": "Introducing Commit",
          "tags": [
            "technical-description",
            "patch"
          ],
          "url": "https://github.com/discourse/discourse/commit/6e37f09b19"
        },
        {
          "name": "Nuclei Template",
          "tags": [
            "technical-description"
          ],
          "url": "https://github.com/projectdiscovery/nuclei-templates/blob/main/http/vulnerabilities/other/discourse-xss.yaml"
        },
        {
          "name": "VulnCheck Advisory: Discourse \u003c 1.9.0.beta13 Reflected XSS via /email/unsubscribed",
          "tags": [
            "third-party-advisory"
          ],
          "url": "https://www.vulncheck.com/advisories/discourse-1.9.0-beta13-reflected-xss-via-email-unsubscribed"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "tags": [
        "x_known-exploited-vulnerability",
        "unsupported-when-assigned"
      ],
      "title": "Discourse \u003c 1.9.0.beta13 Reflected XSS via /email/unsubscribed",
      "x_generator": {
        "engine": "vulncheck-kclub"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "83251b91-4cc7-4094-a5c7-464a1b83ea10",
    "assignerShortName": "VulnCheck",
    "cveId": "CVE-2017-20290",
    "datePublished": "2026-10-22T10:57:24.711Z",
    "dateReserved": "2026-10-14T20:25:25.755Z",
    "dateUpdated": "2026-10-22T10:57:24.711Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}