CVE-2026-33955: Notesnook is a note-taking app

Q: How do I fix CVE-2026-33955?

notesnook desktop: upgrade to 3.3.11. Exact commands for each OS are on this page.

Q: Is CVE-2026-33955 being exploited?

CVE-2026-33955 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

Q: What does CVE-2026-33955 affect?

CVE-2026-33955 affects notesnook desktop. Severity is high (CVSS 8.6). 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

Q: How urgent is CVE-2026-33955?

Priority 42/100. High severity; Public exploit reference

This month

HIGH 8.6UPGRADE

CVE-2026-33955 is a high-severity flaw (CVSS 8.6) affecting notesnook desktop. Below: why it ranks where it does, which versions are affected, what to do, and the exact commands.

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 rem

Why this priority

High severity
Public exploit reference

A fixed release or distro patch exists.

Risk facts

CVSS score	8.6 (High)
Attack vector	Local
Attack complexity	Low
Privileges needed	None
User interaction	Required
EPSS exploit chance	0.4% (top 72%)
CISA exploited list	No
Weakness	CWE-79, CWE-94
Published	2026-03-27
Last modified	2026-10-25

Publisher (CNA): GitHub, Inc. · Vendor: streetwriters

Last updated 2026-10-25 · Sources: CVE Program, NVD, CISA KEV, EPSS and vendor advisories · How we score

Am I affected?

Timeline

2026-03-27 22:16 UTCPublished CVE record published
2026-10-25 23:10 UTCUpdated Record last modified

streetwriters notesnook desktop UPGRADE

Affected: < 3.3.11

Fixed in: 3.3.11

Safe to downgrade to: no unaffected older release

1. Check installed version

apt-cache policy notesnook-desktop || rpm -q notesnook-desktop || notesnook-desktop --version

2. UPGRADE to 3.3.11 (Debian / Ubuntu)

sudo apt update && sudo apt install --only-upgrade notesnook-desktop

2. UPGRADE (RHEL / Amazon Linux / Fedora)

sudo dnf upgrade notesnook-desktop

Note

Distros often backport fixes without changing the version number. Confirm with the distro advisory or changelog.

Verify at the official source NVD · CVE Program · Report a problem with this page
Scores and fixes here are computed automatically from those and other public sources. Confirm with the vendor advisory before changing production systems.

Quick answers

How do I fix CVE-2026-33955?

notesnook desktop: upgrade to 3.3.11. Exact commands for each OS are on this page.

Is CVE-2026-33955 being exploited?

CVE-2026-33955 is not on the CISA Known Exploited Vulnerabilities list at the time of the last update. Check again, as this can change.

What does CVE-2026-33955 affect?

CVE-2026-33955 affects notesnook desktop. Severity is high (CVSS 8.6). 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

How urgent is CVE-2026-33955?

Priority 42/100. High severity; Public exploit reference

References

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