CVE-2026-33978
Prior to version 3.3.17, a stored XSS vulnerability exists in the mobile share / web clip flow because attacker-controlled clip metadata is concatenated into HTML without escaping and then rendered with innerHTML inside the mobile share editor WebView.
Does this matter?
Lower severity and a low EPSS score (0.29%). Track it; it rarely justifies an emergency change on its own.
Description
Notesnook is a note-taking app focused on user privacy & ease of use. Prior to version 3.3.17, a stored XSS vulnerability exists in the mobile share / web clip flow because attacker-controlled clip metadata is concatenated into HTML without escaping and then rendered with innerHTML inside the mobile share editor WebView. An attacker can control the shared title metadata (for example through Android/iOS share metadata such as TITLE / SUBJECT, or through link-preview title data) and inject HTML such as </a><img src=x onerror=...>. When the victim opens the Notesnook share flow and selects Web clip, the payload is inserted into the generated HTML and executed in the mobile editor WebView. This issue has been patched in version 3.3.17.
- CVSS 3.1
- 6.1 MEDIUMCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
- EPSS
- 0.29% probability · 21th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-79
- Affected
- streetwriters/notesnook mobile
- Source
- security-advisories@github.com
References
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.