How severe is CVE-2026-33955?

CVE-2026-33955 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2026-33955 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2026-33955?

CVE-2026-33955 affects Streetwriters Notesnook Desktop. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2026-33955?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

Does CVE-2026-33955 have an EU (EUVD) identifier?

Yes. CVE-2026-33955 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16872.

When was CVE-2026-33955 published?

CVE-2026-33955 was published on 2026-03-27 and last updated on 2026-06-17.

CVE-2026-33955

CVE-2026-33955 is a high-severity vulnerability in Streetwriters Notesnook Desktop with a CVSS 3.x base score of 8.6. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-79.

Key facts

Severity: High (CVSS 3.x base score 8.6)
EPSS exploit prediction: 0% (27th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2026-16872
Weakness: CWE-79
Affected product: Streetwriters Notesnook Desktop
Published: 2026-03-27
Last modified: 2026-06-17

Description

Notesnook is a note-taking app. Prior to version 3.3.11 on Web/Desktop, a cross-site scripting vulnerability stored in the note history comparison viewer can escalate to remote code execution in a desktop application. The issue is triggered when an attacker-controlled note header is displayed using `dangerouslySetInnerHTML` without secure handling. When combined with the full backup and restore feature in the desktop application, this becomes remote code execution because Electron is configured with `nodeIntegration: true` and `contextIsolation: false`. Version 3.3.11 patches the issue.

Frequently asked questions

What is CVE-2026-33955?: Notesnook is a note-taking app. Prior to version 3.3.11 on Web/Desktop, a cross-site scripting vulnerability stored in the note history comparison viewer can escalate to remote code execution in a desktop application. The issue is triggered when an attacker-controlled note header is displayed using `dangerouslySetInnerHTML` without secure handling. When combined with the full backup and restore feature in the desktop application, this becomes remote code execution because Electron is configured with `nodeIntegration: true` and `contextIsolation: false`. Version 3.3.11 patches the issue.
How severe is CVE-2026-33955?: CVE-2026-33955 has a CVSS 3.x base score of 8.6, rated high severity. It is exploitable over local access with low attack complexity, requires no privileges and user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2026-33955 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 0% (27th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2026-33955?: CVE-2026-33955 affects Streetwriters Notesnook Desktop. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2026-33955?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
Does CVE-2026-33955 have an EU (EUVD) identifier?: Yes. CVE-2026-33955 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2026-16872.
When was CVE-2026-33955 published?: CVE-2026-33955 was published on 2026-03-27 and last updated on 2026-06-17.

References

https://github.com/streetwriters/notesnook/security/advisories/GHSA-45g3-cv93-q59v

Affected products (1)

cpe:2.3:a:streetwriters:notesnook_desktop:*:*:*:*:*:*:*:*

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