{"id":"CVE-2026-33976","state":"PUBLISHED","title":"Notesnook vulnerable to RCE via stored XSS in Web Clipper rendering","description":"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.","publishedAt":"2026-03-27T21:26:10.127Z","updatedAt":"2026-04-03T03:55:22.486Z","severity":{"score":9.7,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","source":"GitHub_M"},"assigner":"GitHub_M","products":["streetwriters Notesnook Web/Desktop","streetwriters Notesnook iOS/Android"],"affected":[{"vendor":"streetwriters","product":"Notesnook Web/Desktop","versions":[{"version":"< 3.3.11","status":"affected"}]},{"vendor":"streetwriters","product":"Notesnook iOS/Android","versions":[{"version":"< 3.3.17","status":"affected"}]}],"references":["https://github.com/streetwriters/notesnook/security/advisories/GHSA-f42f-phvp-43x5"],"weaknesses":["CWE-79","CWE-94"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/33xxx/CVE-2026-33976.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-33976","state":"PUBLISHED","datePublished":"2026-03-27T21:26:10.127Z","dateUpdated":"2026-04-03T03:55:22.486Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-03-24T22:20:06.210Z"},"containers":{"cna":{"title":"Notesnook vulnerable to RCE via stored XSS in Web Clipper rendering","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"streetwriters","product":"Notesnook Web/Desktop","versions":[{"version":"< 3.3.11","status":"affected"}]},{"vendor":"streetwriters","product":"Notesnook iOS/Android","versions":[{"version":"< 3.3.17","status":"affected"}]}],"references":[{"url":"https://github.com/streetwriters/notesnook/security/advisories/GHSA-f42f-phvp-43x5","name":"https://github.com/streetwriters/notesnook/security/advisories/GHSA-f42f-phvp-43x5","tags":["x_refsource_CONFIRM"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"NETWORK","availabilityImpact":"HIGH","baseScore":9.7,"baseSeverity":"CRITICAL","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"NONE","scope":"CHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-79","lang":"en","description":"CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')","type":"CWE"}]},{"descriptions":[{"cweId":"CWE-94","lang":"en","description":"CWE-94: Improper Control of Generation of Code ('Code Injection')","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-03-27T21:26:10.127Z"},"source":{"advisory":"GHSA-f42f-phvp-43x5","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-03-31T00:00:00+00:00","options":[{"Exploitation":"poc"},{"Automatable":"no"},{"Technical Impact":"total"}],"role":"CISA Coordinator","version":"2.0.3","id":"CVE-2026-33976"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-03T03:55:22.486Z"}}]}}}