Is CVE-2026-40263 actively exploited?

No active exploitation of CVE-2026-40263 has been confirmed so far. Continue monitoring, as exploit status can change.

Can CVE-2026-40263 be exploited remotely?

Yes. CVE-2026-40263 is exploitable remotely over the network (CVSS attack vector: Network).

What is the CVSS score of CVE-2026-40263?

CVE-2026-40263 has a CVSS score of 3.7 (LOW).

HOME VULNERABILITIESCVE-2026-40263

LOW

CVE-2026-40263

CWE-208Published: April 17, 2026· Updated: Apr 17, 2026

3.7

CVSS v3.1

EPSS:0.03%probability of exploitation in 30 daysPercentile:8.2th

Official Description

Note Mark is an open-source note-taking application. In versions 0.19.1 and prior, the login endpoint performs bcrypt password verification only when the supplied username exists, returning immediately for nonexistent usernames. This timing discrepancy allows unauthenticated attackers to enumerate valid usernames by measuring response times, enabling targeted credential attacks. This issue has been fixed in version 0.19.2.

NVD Source

Technical Analysis

CVE-2026-40263 can be exploited remotely over the network without requiring physical or adjacent access, significantly expanding the attack surface for threat actors.

The vulnerability requires no privileges and no user interaction, making it a prime target for automated exploitation campaigns and worm-like propagation.