VulnerabilityPublished 10 Jul 2026

CVE-2026-50554: Note Mark · Unauthenticated disclosure of soft-deleted note metadata via deleted=true on public books

Affects github.com/enchant97/note-mark/backendSource GCVE Database

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Authoritative record:CVE-2026-50554· Medium 5.3

Not known to be exploited · CVSS 5.3 Medium : upgrade to 0.0.0-20260601210758-9c9b72740f22 when convenient.

Data as of 29 Oct 2026, 19:04 UTC

CVSS 3.1 base score

5.3Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 35% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
Patch: Available – fixed in 0.0.0-20260601210758-9c9b72740f22

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Unchanged
Confidentiality: Low
Integrity: None
Availability: None

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Unchanged: An exploited vulnerability can only affect resources managed by the same security authority. In this case, the vulnerable component and the impacted component are either the same, or both are managed by the same security authority.
Confidentiality: Low: There is some loss of confidentiality. Access to some restricted information is obtained, but the attacker does not have control over what information is obtained, or the amount or kind of loss is limited. The information disclosure does not cause a direct, serious loss to the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: None: There is no impact to availability within the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

t = 0 is the CVE’s publication on cve.org

Disclosed: evidence found.
CVE published 3 Sep 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: evidence found.
CISA SSVC: proof of concept public
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

CVE ID reserved
by GitHub, Inc.
4 Jun 202621:34 UTC, 91 days before disclosure
CVE published
on cve.org
3 Sep 202615:26 UTC, t = 0
CISA SSVC assessment
proof of concept public
3 Sep 202615:56 UTC, 29 minutes after disclosure

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), CISA SSVC, the Metasploit, Exploit-DB and nuclei-templates index as of 29 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Upgrade github.com/enchant97/note-mark/backend to 0.0.0-20260601210758-9c9b72740f22.

Affected software

Product	Affected	Fixed in
Gogithub.com/enchant97/note-mark/backend	Affected <0.0.0-20260601210758-9c9b72740f22	Fixed in 0.0.0-20260601210758-9c9b72740f22

Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.

AI-suggested

A patch is available that restricts access to soft-deleted notes exclusively to the book owner, preventing unauthenticated users from retrieving metadata of trashed notes in public books. Users of the affected Note Mark backend should apply the official fix to enforce proper authorization on the 'deleted=true' query parameter. No additional mitigation is indicated by the vendor advisory.

Description

Note Mark is an open-source note-taking application. Prior to version 0.19.5, GET /api/books/{bookID}/notes is an unauthenticated endpoint that accepts a "deleted" query parameter. When the request is ?deleted=true, the service runs the query with Unscoped() (bypassing GORM's soft-delete scope) but keeps the read-authorization clause as "owner_id = ? OR is_public = ?". As a result, any unauthenticated caller can enumerate the metadata of soft-deleted ("trashed") notes belonging to any public book — notes the owner explicitly deleted and expected to be removed from public view. This issue has been patched in version 0.19.5.

Impact

This vulnerability leads to unauthorized disclosure of metadata for soft-deleted notes in public books to unauthenticated users. Although the note content is not exposed, sensitive metadata such as note identifiers and timestamps may reveal information the note owner intended to keep hidden. There is no impact on data integrity or availability. The CVSS 3.1 base score is 5.3 (medium severity), reflecting low impact on confidentiality and no impact on integrity or availability.

Summary

The Note Mark backend has an unauthenticated API endpoint GET /api/books/{bookID}/notes that accepts a 'deleted=true' query parameter. When used on public books, this parameter bypasses the soft-delete filter, allowing unauthenticated users to access metadata of soft-deleted (trashed) notes. The exposed metadata includes note ID, title, slug, and timestamps, but not the note content. The root cause is improper authorization logic failing to limit soft-deleted note visibility to the note owner. A code fix involves restricting soft-deleted note listings to the book owner only, preventing public access to trashed notes.

CWE-200Exposure of Sensitive Information to an Unauthorized Actor (opens in a new tab)
Class weaknessLikelihood of exploit: HighCWE Top 25 (2025): #20OWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product exposes sensitive information to an actor that is not explicitly authorized to have access to that information.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design · Separation of Privilege
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.
OWASP Cheat Sheets
Error Handling (opens in a new tab)
Logging (opens in a new tab)
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.4 (opens in a new tab)
V14.3.3 (opens in a new tab)
V7.3.3 (opens in a new tab)
Attack patterns
Subverting Environment Variable Values (opens in a new tab)
ICMP Echo Request Ping (opens in a new tab)
TCP SYN Scan (opens in a new tab)
Enumerate Mail Exchange (MX) Records (opens in a new tab)
DNS Zone Transfers (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).
CWE-285Improper Authorization (opens in a new tab)
Class weaknessLikelihood of exploit: HighOWASP Top 10 A01:2025: Broken Access Control (opens in a new tab)
The product does not perform or incorrectly performs an authorization check when an actor attempts to access a resource or perform an action.
MITRE discourages mapping vulnerabilities to this broad entry; the root cause is usually a more specific weakness.
Architecture and Design
Divide the product into anonymous, normal, privileged, and administrative areas. Reduce the attack surface by carefully mapping roles with data and functionality. Use role-based access control (RBAC) to enforce the roles at the appropriate boundaries.
Architecture and Design
Ensure that you perform access control checks related to your business logic. These checks may be different than the access control checks that you apply to more generic resources such as files, connections, processes, memory, and database records.
Architecture and Design · Libraries or Frameworks
Use a vetted library or framework that does not allow this weakness to occur or provides constructs that make this weakness easier to avoid.
OWASP Cheat Sheets
Authorization (opens in a new tab)
OWASP ASVS 4.0.3
V8.3.8 (opens in a new tab)
V13.4.2 (opens in a new tab)
V7.2.2 (opens in a new tab)
Attack patterns
Accessing Functionality Not Properly Constrained by ACLs (opens in a new tab)
Cross Zone Scripting (opens in a new tab)
Directory Indexing (opens in a new tab)
Subverting Environment Variable Values (opens in a new tab)
Using Malicious Files (opens in a new tab)
From MITRE CWE, MITRE CAPEC and OWASP (Top 10, OpenCRE).

References

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Exploitation evidence

Timeline

What to do

Affected software

Description

AI analysisMachine-generated, updated 7 Sep 2026, 11:06 UTC

WeaknessesCWE-200, CWE-285

Technical details

References

Community reviews

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