CVE-2026-55105 (GCVE-0-2026-55105)

Vulnerability from cvelistv5 – Published: 2026-09-21 20:59 – Updated: 2026-09-21 20:59
VLAI
Title
Joplin: Fountain embeds allow arbitrary script execution in published notes and the note viewer
Summary
Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, packages/renderer/MdToHtml/rules/fountain.ts passes HTML generated by the vendored fountain.js renderer into note output without sanitizing it. A malicious Fountain code block can therefore execute script when Fountain rendering is enabled in desktop or mobile clients, or when a note is published through Joplin Server where Fountain rendering is enabled by default. The script can read content subsequently loaded in the reused note viewer or, when published notes are served from the same domain as server content, access data available to an authenticated browser in the server origin. This issue is fixed in versions 3.6.15 and 3.7.2.
Severity
7.7 (High)
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N
CWE
  • CWE-79 - Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')
Assigner
References
Impacted products
Vendor Product Version CPE status
laurent22 joplin Affected: < 3.6.15
Affected: >= 3.7.0, < 3.7.2
guessed Create a notification for this product.
Show details on NVD website
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{
  "containers": {
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      "affected": [
        {
          "product": "joplin",
          "vendor": "laurent22",
          "versions": [
            {
              "status": "affected",
              "version": "\u003c 3.6.15"
            },
            {
              "status": "affected",
              "version": "\u003e= 3.7.0, \u003c 3.7.2"
            }
          ]
        }
      ],
      "descriptions": [
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          "lang": "en",
          "value": "Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, packages/renderer/MdToHtml/rules/fountain.ts passes HTML generated by the vendored fountain.js renderer into note output without sanitizing it. A malicious Fountain code block can therefore execute script when Fountain rendering is enabled in desktop or mobile clients, or when a note is published through Joplin Server where Fountain rendering is enabled by default. The script can read content subsequently loaded in the reused note viewer or, when published notes are served from the same domain as server content, access data available to an authenticated browser in the server origin. This issue is fixed in versions 3.6.15 and 3.7.2."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 7.7,
            "baseSeverity": "HIGH",
            "confidentialityImpact": "HIGH",
            "integrityImpact": "NONE",
            "privilegesRequired": "LOW",
            "scope": "CHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-79",
              "description": "CWE-79: Improper Neutralization of Input During Web Page Generation (\u0027Cross-site Scripting\u0027)",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-21T20:59:52.292Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/laurent22/joplin/security/advisories/GHSA-f7q3-3grx-6wg9",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/laurent22/joplin/security/advisories/GHSA-f7q3-3grx-6wg9"
        },
        {
          "name": "https://github.com/laurent22/joplin/pull/15659",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/laurent22/joplin/pull/15659"
        },
        {
          "name": "https://github.com/laurent22/joplin/commit/8e0812de9d79d1f0698bb76a8c5d7e991df9748d",
          "tags": [
            "x_refsource_MISC"
          ],
          "url": "https://github.com/laurent22/joplin/commit/8e0812de9d79d1f0698bb76a8c5d7e991df9748d"
        }
      ],
      "source": {
        "advisory": "GHSA-f7q3-3grx-6wg9",
        "discovery": "UNKNOWN"
      },
      "title": "Joplin: Fountain embeds allow arbitrary script execution in published notes and the note viewer"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-55105",
    "datePublished": "2026-09-21T20:59:52.292Z",
    "dateReserved": "2026-06-16T14:41:54.579Z",
    "dateUpdated": "2026-09-21T20:59:52.292Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2",
  "vulnerability-lookup:meta": {
    "nvd": {
      "cve": {
        "affected": [
          {
            "affectedData": [
              {
                "product": "joplin",
                "vendor": "laurent22",
                "versions": [
                  {
                    "status": "affected",
                    "version": "\u003c 3.6.15"
                  },
                  {
                    "status": "affected",
                    "version": "\u003e= 3.7.0, \u003c 3.7.2"
                  }
                ]
              }
            ],
            "source": "security-advisories@github.com"
          }
        ],
        "cveTags": [],
        "descriptions": [
          {
            "lang": "en",
            "value": "Joplin is an open source note-taking and to-do application that organises notes and lists into notebooks. Prior to 3.6.15 and 3.7.2, packages/renderer/MdToHtml/rules/fountain.ts passes HTML generated by the vendored fountain.js renderer into note output without sanitizing it. A malicious Fountain code block can therefore execute script when Fountain rendering is enabled in desktop or mobile clients, or when a note is published through Joplin Server where Fountain rendering is enabled by default. The script can read content subsequently loaded in the reused note viewer or, when published notes are served from the same domain as server content, access data available to an authenticated browser in the server origin. This issue is fixed in versions 3.6.15 and 3.7.2."
          }
        ],
        "id": "CVE-2026-55105",
        "lastModified": "2026-09-21T21:17:05.320",
        "metrics": {
          "cvssMetricV31": [
            {
              "cvssData": {
                "attackComplexity": "LOW",
                "attackVector": "NETWORK",
                "availabilityImpact": "NONE",
                "baseScore": 7.7,
                "baseSeverity": "HIGH",
                "confidentialityImpact": "HIGH",
                "integrityImpact": "NONE",
                "privilegesRequired": "LOW",
                "scope": "CHANGED",
                "userInteraction": "NONE",
                "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N",
                "version": "3.1"
              },
              "exploitabilityScore": 3.1,
              "impactScore": 4.0,
              "source": "security-advisories@github.com",
              "type": "Secondary"
            }
          ]
        },
        "published": "2026-09-21T21:17:05.320",
        "references": [
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/laurent22/joplin/commit/8e0812de9d79d1f0698bb76a8c5d7e991df9748d"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/laurent22/joplin/pull/15659"
          },
          {
            "source": "security-advisories@github.com",
            "url": "https://github.com/laurent22/joplin/security/advisories/GHSA-f7q3-3grx-6wg9"
          }
        ],
        "sourceIdentifier": "security-advisories@github.com",
        "vulnStatus": "Received",
        "weaknesses": [
          {
            "description": [
              {
                "lang": "en",
                "value": "CWE-79"
              }
            ],
            "source": "security-advisories@github.com",
            "type": "Primary"
          }
        ]
      }
    }
  }
}



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Forecast uses a logistic model when the trend is rising, or an exponential decay model when the trend is falling. Fitted via linearized least squares.

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