CVE-2026-40262

Note Mark has Stored XSS via Unrestricted Asset Upload

HIGH
8.7
CVSS Score
Published: April 16, 2026 at 11:51 PM UTC
Updated: June 17, 2026 at 10:44 AM UTC
1 product affected across 1 vendorNote Mark

Using note-mark by enchant97?

Get instant alerts when new vulnerabilities affect note-mark - before attackers find them.

Real-time alertsTrack your software stackFree plan available
Severity
HIGH8.7
Exploit prediction
EPSS 0.3%
SSVC
PoC

Description

Note Mark is an open-source note-taking application. In versions 0.19.1 and prior, the asset delivery handler serves uploaded files inline and relies on magic-byte detection for content type, which does not identify text-based formats such as HTML, SVG, or XHTML. These files are served with an empty Content-Type, no X-Content-Type-Options: nosniff header, and inline disposition, allowing browsers to sniff and render active content. An authenticated user can upload an HTML or SVG file containing JavaScript as a note asset, and when a victim navigates to the asset URL, the script executes under the application's origin with access to the victim's authenticated session and API actions. This issue has been fixed in version 0.19.2.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

v < 0.19.2
Affected range stops below 0.19.2, so it looks safe — our inference, not a vendor statement

Remediation

No guide yet

No remediation guidance has been written for this CVE yet, and no fixed version or vendor advisory is recorded against it.

SSVC — Action Prioritization

SSVCPoCNot automatableTotal impact

SSVC signals action urgency (what to patch first), separate from CVSS which measures severity.

CVSS

8.7HIGHGitHub_M
Attack Vector
NETWORK
Complexity
LOW
Privileges
LOW
User Interaction
REQUIRED
Scope
CHANGED
Confidentiality
HIGH
Integrity
HIGH
Availability
NONE
Vector?

Quick Info

StatusDEFERRED
CWE
CWE-79CWE-434

Get alerted

Stop reading CVE feeds looking for your own stack

Track the products you run and VulnTracker tells you when a new CVE affects them — with what is known about fixing it, and nothing about the rest.

Free plan, no card