CVE-2026-40265 enchant97 CVE debrief

Who should care

Defenders responsible for Note Mark instances, especially those with private notes, should assess exposure and prioritize upgrading to version 0.19.2. This includes verifying exposure of Note Mark instances with private notes, reviewing and updating access controls for note assets, and ensuring that Note Mark instances are running version 0.19.2 or later.

Why it matters

CVE-2026-40265 is a medium-severity vulnerability in Note Mark that allows unauthenticated access to private note assets. Defenders should prioritize verifying exposure and upgrading to version 0.19.2.

• Verify exposure of Note Mark instances with private notes
• Upgrade to version 0.19.2 or later to prevent unauthenticated asset access
• Review and update access controls for note assets

Technical summary

The asset download endpoint in Note Mark versions 0.19.1 and prior is vulnerable to unauthenticated access, allowing retrieval of private note assets. This issue has been fixed in version 0.19.2. The vulnerability allows unauthenticated users who know a valid note ID and asset ID to retrieve the full contents of private note assets without authentication. Defenders should prioritize verifying exposure of Note Mark instances, especially those with private notes, and upgrade to version 0.19.2 or later to prevent unauthenticated asset access.

Defensive priority

Defenders should prioritize verifying exposure of Note Mark instances, especially those with private notes, and upgrade to version 0.19.2.

Recommended defensive actions

• Verify Note Mark instance exposure, especially for private notes
• Upgrade to version 0.19.2 or later
• Review and update access controls for note assets
• Confirm whether affected product deployments exist in managed environments and assign an owner for follow-up
• Review compensating controls for exposed systems while remediation is scheduled and verified
• Check relevant monitoring, detection, and logs for exposed assets that need extra review
• Track exceptions, retest remediated assets, and close the item only after evidence is documented

Evidence notes

The CVE record and NVD entry provide details on the unauthenticated asset download vulnerability in Note Mark versions 0.19.1 and prior. The vulnerability allows unauthenticated users to retrieve private note assets without authentication. The issue is fixed in version 0.19.2. Defenders should verify exposure and upgrade to version 0.19.2 or later. The CVE record was published on 2026-04-17T01:17:40.293Z and has not been modified since then. This information is based on the CVE record and NVD entry, which provide source-provided CVE 0

Sources and references

Methodology and review provenance

AI-assisted synthesis based on stored public vulnerability evidence. System validation, approval state, and publication status do not by themselves establish human review of this revision. PatchSiren helps prioritize defensive review and does not prove exposure or remediation on any system.