{
    "document": {
        "category": "csaf_base",
        "csaf_version": "2.0",
        "distribution": {
            "tlp": {
                "label": "WHITE"
            }
        },
        "lang": "en",
        "notes": [
            {
                "category": "legal_disclaimer",
                "text": "The Netherlands Cyber Security Center (henceforth: NCSC-NL) maintains this portal to enhance access to its information and vulnerabilities. The use of this information is subject to the following terms and conditions:\n\nThe vulnerabilities disclosed in this portal are gathered by NCSC-NL from a variety of open sources, which the user can retrieve from other platforms. NCSC-NL makes every reasonable effort to ensure that the content of this portal is kept up to date, and that it is accurate and complete. Nevertheless, NCSC-NL cannot entirely rule out the possibility of errors, and therefore cannot give any warranty in respect of its completeness, accuracy or real-time keeping up-to-date. NCSC-NL does not control nor guarantee the accuracy, relevance, timeliness or completeness of information obtained from these external sources. The vulnerabilities disclosed in this portal are intended solely for the convenience of professional parties to take appropriate measures to manage the risks posed to the cybersecurity. No rights can be derived from the information provided therein.\n\nNCSC-NL and the Kingdom of the Netherlands assume no legal liability or responsibility for any damage resulting from either the use or inability of use of the vulnerabilities disclosed in this portal. This includes damage resulting from the inaccuracy of incompleteness of the information contained in it.\nThe information on this page is subject to Dutch law. All disputes related to or arising from the use of this portal regarding the disclosure of vulnerabilities will be submitted to the competent court in The Hague. This choice of means also applies to the court in summary proceedings."
            }
        ],
        "publisher": {
            "category": "coordinator",
            "contact_details": "cert@ncsc.nl",
            "name": "National Cyber Security Centre",
            "namespace": "https://www.ncsc.nl/"
        },
        "title": "CVE-2026-33976",
        "tracking": {
            "current_release_date": "2026-04-03T04:40:45.314266Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-33976",
            "initial_release_date": "2026-03-28T07:39:55.758734Z",
            "revision_history": [
                {
                    "date": "2026-03-28T07:39:55.758734Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-28T07:39:57.537084Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                },
                {
                    "date": "2026-03-28T07:40:18.931390Z",
                    "number": "3",
                    "summary": "Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| Products connected (1).| Products created (1).| References created (1).| CWES updated (1)."
                },
                {
                    "date": "2026-03-28T07:40:22.981132Z",
                    "number": "4",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-03-29T00:38:28.791670Z",
                    "number": "5",
                    "summary": "Source connected.| CVE status created. (valid)| EPSS created."
                },
                {
                    "date": "2026-03-30T16:39:08.664301Z",
                    "number": "6",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-03-31T18:25:27.811105Z",
                    "number": "7",
                    "summary": "Products created (2).| Product Identifiers created (2).| Exploits created (1)."
                },
                {
                    "date": "2026-03-31T18:25:30.383531Z",
                    "number": "8",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-01T05:38:48.679908Z",
                    "number": "9",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-04-02T12:30:52.696271Z",
                    "number": "10",
                    "summary": "NCSC Score updated."
                },
                {
                    "date": "2026-04-03T04:38:47.533958Z",
                    "number": "11",
                    "summary": "Unknown change."
                },
                {
                    "date": "2026-04-03T04:38:50.223308Z",
                    "number": "12",
                    "summary": "NCSC Score updated."
                }
            ],
            "status": "interim",
            "version": "12"
        }
    },
    "product_tree": {
        "branches": [
            {
                "branches": [
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<3.3.11",
                                "product": {
                                    "name": "vers:unknown/<3.3.11",
                                    "product_id": "CSAFPID-5956295"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Notesnook Web/Desktop"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<3.3.17",
                                "product": {
                                    "name": "vers:unknown/<3.3.17",
                                    "product_id": "CSAFPID-5956296"
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "Notesnook iOS/Android"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<3.3.11",
                                "product": {
                                    "name": "vers:unknown/<3.3.11",
                                    "product_id": "CSAFPID-5969391",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:streetwriters:notesnook_desktop:*:*:*:*:*:*:*:*"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "notesnook_desktop"
                    },
                    {
                        "branches": [
                            {
                                "category": "product_version_range",
                                "name": "vers:unknown/<3.3.17",
                                "product": {
                                    "name": "vers:unknown/<3.3.17",
                                    "product_id": "CSAFPID-5969392",
                                    "product_identification_helper": {
                                        "cpe": "cpe:2.3:a:streetwriters:notesnook_mobile:*:*:*:*:*:android:*:*"
                                    }
                                }
                            }
                        ],
                        "category": "product_name",
                        "name": "notesnook_mobile"
                    }
                ],
                "category": "vendor",
                "name": "streetwriters"
            }
        ]
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-33976",
            "cwe": {
                "id": "CWE-79",
                "name": "Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "Notesnook is a note-taking app. Prior to version 3.3.11 on Web/Desktop and 3.3.17 on Android/iOS, a stored XSS in the Web Clipper rendering flow can be escalated to remote code execution in the desktop app. The root cause is that the clipper preserves attacker-controlled attributes from the source page’s root element and stores them inside web-clip HTML. When the clip is later opened, Notesnook renders that HTML into a same-origin, unsandboxed iframe using `contentDocument.write(...)`. Event-handler attributes such as `onload`, `onclick`, or `onmouseover` execute in the Notesnook origin. In the desktop app, this becomes RCE because Electron is configured with `nodeIntegration: true` and `contextIsolation: false`. Version 3.3.11 Web/Desktop and 3.3.17 on Android/iOS patch the issue.",
                    "title": "nvd - https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33976"
                },
                {
                    "category": "description",
                    "text": "Notesnook is a note-taking app. Prior to version 3.3.11 on Web/Desktop and 3.3.17 on Android/iOS, a stored XSS in the Web Clipper rendering flow can be escalated to remote code execution in the desktop app. The root cause is that the clipper preserves attacker-controlled attributes from the source page’s root element and stores them inside web-clip HTML. When the clip is later opened, Notesnook renders that HTML into a same-origin, unsandboxed iframe using `contentDocument.write(...)`. Event-handler attributes such as `onload`, `onclick`, or `onmouseover` execute in the Notesnook origin. In the desktop app, this becomes RCE because Electron is configured with `nodeIntegration: true` and `contextIsolation: false`. Version 3.3.11 Web/Desktop and 3.3.17 on Android/iOS patch the issue.",
                    "title": "cveprojectv5 - https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33976.json"
                },
                {
                    "category": "other",
                    "text": "0.00136",
                    "title": "EPSS"
                },
                {
                    "category": "other",
                    "text": "4.2",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "There is exploit data available from source Nvd, Exploit code publicly available",
                    "title": "NCSC Score top decreasing factors"
                }
            ],
            "product_status": {
                "known_affected": [
                    "CSAFPID-5956295",
                    "CSAFPID-5956296",
                    "CSAFPID-5969391",
                    "CSAFPID-5969392"
                ]
            },
            "references": [
                {
                    "category": "external",
                    "summary": "Source - nvd",
                    "url": "https://services.nvd.nist.gov/rest/json/cves/2.0?cveId=CVE-2026-33976"
                },
                {
                    "category": "external",
                    "summary": "Source - cveprojectv5",
                    "url": "https://raw.githubusercontent.com/CVEProject/cvelistV5/main/cves/2026/33xxx/CVE-2026-33976.json"
                },
                {
                    "category": "external",
                    "summary": "Source - first",
                    "url": "https://api.first.org/data/v1/epss?limit=10000&offset=0"
                },
                {
                    "category": "external",
                    "summary": "Reference - cveprojectv5; nvd",
                    "url": "https://github.com/streetwriters/notesnook/security/advisories/GHSA-f42f-phvp-43x5"
                }
            ],
            "scores": [
                {
                    "cvss_v3": {
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H",
                        "baseScore": 9.6,
                        "baseSeverity": "CRITICAL"
                    },
                    "products": [
                        "CSAFPID-5956295",
                        "CSAFPID-5956296",
                        "CSAFPID-5969391",
                        "CSAFPID-5969392"
                    ]
                }
            ],
            "title": "CVE-2026-33976"
        }
    ]
}