CVE-2026-40265Public exploitNetwork attack vector

Private asset disclosure via unauthenticated download route

Published Apr 16, 2026 · Updated Apr 16, 2026

Missing authorization in Note Mark 0.19.1 and earlier allows remote attackers to read private note assets via its download API. The GET route in handlers/assets.go omits authentication middleware, while its database lookup checks only supplied note and asset IDs without enforcing ownership or book visibility. Exploitation requires both UUIDv4 identifiers, but disclosure through shared links, browser history, or logs exposes the asset's full binary contents.

CVSS severity5.9
Medium
EPSS probability0.44%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Missing authorization in Note Mark 0.19.1 and earlier allows remote attackers to read private note assets via its download API. The GET route in handlers/assets.go omits authentication middleware, while its database lookup checks only supplied note and asset IDs without enforcing ownership or book visibility. Exploitation requires both UUIDv4 identifiers, but disclosure through shared links, browser history, or logs exposes the asset's full binary contents.

The record

CVE
CVE-2026-40265
Published
Apr 16, 2026
Updated
Apr 16, 2026
Vendor
Leo Spratt
Product
Note Mark
Classifications
CWE-862, T1190
Attack vector
network
Privileges
unauthenticated

Timeline

How it unfolded

  1. Apr 16, 2026CVE publishedPublication date reported by the CVE source.
  2. Apr 16, 2026Record updatedLatest update available in the CVE record.

Exploitability

Present is not the same as exploitable

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Is a vulnerable build present?

Compare these published version ranges with your installed build and any vendor patches.

  1. Affected versionversion=< 0.19.2

What conditions does exploitation require?

Attack vectornetwork
Required privilegesunauthenticated

What is affected?

Leo Spratt · Note Markversion=< 0.19.2

Published CVSS scores

5.9GitHubCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N

CVSS describes severity. EPSS estimates exploitation probability.

Attacks

What attackers are doing with it

Daily unique IPs observed by Shadowserver honeypots for known exploited vulnerabilities (KEVs). Missing observations do not establish an absence of attacks.

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No observations available

Sep 10, 2026Sep 16, 2026
Latest reporting daySep 16, 2026
Latest daily unique IPsUnavailable
Prior 30-day averageUnavailable
SourceShadowserver honeypots (KEV)
Vectornetwork
Privilegesunauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-862Missing Authorization
T1190Exploit Public-Facing Application

Public exploit references

Labels summarize the accepted research assessment. They do not indicate a test against your environment.

Technologies

Your stack

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Your stack

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