{
    "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-2026-34778",
        "tracking": {
            "current_release_date": "2026-04-03T03:43:26.758070Z",
            "generator": {
                "date": "2026-02-17T15:00:00Z",
                "engine": {
                    "name": "V.E.L.M.A",
                    "version": "1.7"
                }
            },
            "id": "CVE-2026-34778",
            "initial_release_date": "2026-04-03T03:41:43.965078Z",
            "revision_history": [
                {
                    "date": "2026-04-03T03:41:43.965078Z",
                    "number": "1",
                    "summary": "CVE created.| Source created.| CVE status created. (valid)| Description created for source.| CVSS created.| References created (2).| CWES updated (1)."
                },
                {
                    "date": "2026-04-03T03:41:52.426655Z",
                    "number": "2",
                    "summary": "NCSC Score created."
                }
            ],
            "status": "interim",
            "version": "2"
        }
    },
    "vulnerabilities": [
        {
            "cve": "CVE-2026-34778",
            "cwe": {
                "id": "CWE-290",
                "name": "Authentication Bypass by Spoofing"
            },
            "notes": [
                {
                    "category": "description",
                    "text": "### Impact\nA service worker running in a session could spoof reply messages on the internal IPC channel used by `webContents.executeJavaScript()` and related methods, causing the main-process promise to resolve with attacker-controlled data.\n\nApps are only affected if they have service workers registered and use the result of `webContents.executeJavaScript()` (or `webFrameMain.executeJavaScript()`) in security-sensitive decisions.\n\n### Workarounds\nDo not trust the return value of `webContents.executeJavaScript()` for security decisions. Use dedicated, validated IPC channels for security-relevant communication with renderers.\n\n### Fixed Versions\n* `41.0.0`\n* `40.8.1`\n* `39.8.1`\n* `38.8.6`\n\n### For more information\nIf there are any questions or comments about this advisory, please email [security@electronjs.org](mailto:security@electronjs.org)",
                    "title": "github - https://api.github.com/advisories/GHSA-xj5x-m3f3-5x3h"
                },
                {
                    "category": "other",
                    "text": "3.9",
                    "title": "NCSC Score"
                },
                {
                    "category": "other",
                    "text": "Is related to CWE-345 (Insufficient Verification of Data Authenticity)",
                    "title": "NCSC Score top increasing factors"
                }
            ],
            "references": [
                {
                    "category": "external",
                    "summary": "Source - github",
                    "url": "https://api.github.com/advisories/GHSA-xj5x-m3f3-5x3h"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/electron/electron/security/advisories/GHSA-xj5x-m3f3-5x3h"
                },
                {
                    "category": "external",
                    "summary": "Reference - github",
                    "url": "https://github.com/advisories/GHSA-xj5x-m3f3-5x3h"
                }
            ],
            "title": "CVE-2026-34778"
        }
    ]
}