CVE-2026-33978

MEDIUM EPSS 20.3%
Published Apr 1, 20263mo ago · Modified Jun 17, 20262w ago
6.1 CVSS 3.1
Medium
Find Similar
Published Apr 1, 2026 3mo ago
Last Modified Jun 17, 2026 2w ago

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 Details

Base Score
6.1
Exploitability
2.8
Impact
2.7
Vector string
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
Attack Vector Network
Attack Complexity Low
Privileges Required None
User Interaction Required
Scope Changed
Confidentiality Low
Integrity Low
Availability None

Threat Intelligence

EPSS Exploit Probability
20.3% percentile
Exploit & Patch Status
Public Exploit Known
Patch Available

Weaknesses 1

CWE-79 Cross-site Scripting Injection

Affected Products 2

VendorProductVersionRange
streetwritersnotesnook_mobile* <3.3.17
streetwritersnotesnook_mobile* <3.3.17

References 3

  • github.com https://github.com/streetwriters/notesnook/commit/fc8807f74db5539036c5e58d3d68a11ea54098db
    Patch
  • github.com https://github.com/streetwriters/notesnook/releases/tag/3.3.17-android
    Release Notes
  • github.com https://github.com/streetwriters/notesnook/security/advisories/GHSA-f27j-fqc6-v7pm
    ExploitVendor Advisory

Remediation

  • github.com https://github.com/streetwriters/notesnook/commit/fc8807f74db5539036c5e58d3d68a11ea54098db
    Patch