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CVE-2026-33976

Streetwriters Notesnook Mobile remote code execution

9.6 CRITICALPublic exploitEPSS 0.69%
  1. Published27 Mar 2026

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.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionRequired
ScopeChanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H

Affected products

Streetwriters Notesnook Desktop< 3.3.11
Streetwriters Notesnook Mobile< 3.3.17

Remediation

Fixed in
Streetwriters Notesnook Desktop≥ 3.3.11
Streetwriters Notesnook Mobile≥ 3.3.17

References

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Frequently asked

Is CVE-2026-33976 being actively exploited?

CVE-2026-33976 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.69%.

How severe is CVE-2026-33976?

CVE-2026-33976 has a CVSS 3.1 base score of 9.6, rated critical. EPSS estimates a 0.69% probability of exploitation.

Which products are affected by CVE-2026-33976?

Affected products include Streetwriters Notesnook Desktop, Streetwriters Notesnook Mobile.

How do I fix CVE-2026-33976?

Upgrade affected software to a fixed version, for example Streetwriters Notesnook Desktop 3.3.11, Streetwriters Notesnook Mobile 3.3.17 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-33976 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

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Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.