CVE-2026-28506Public exploitNetwork attack vector

Authenticated metadata disclosure via null-collection event filtering

Published Mar 17, 2026 · Updated Mar 17, 2026

Information disclosure in Outline before 1.5.0 allows remote authenticated users to read private-document metadata via events.list. The server/routes/api/events/events.ts query treats every event with a null collectionId as global without checking actorId or document ownership, exposing events for private drafts and deleted documents. Any regular member can obtain document IDs, activity timestamps, and some permanently deleted document titles, but not document content directly.

CVSS severity4.3
Medium
EPSS probability0.23%
Next 30 days · Sep 16, 2026
Known exploitationUnconfirmed
Based on sourced intelligence
Hinoki checkNot available
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Summary

What happened

Information disclosure in Outline before 1.5.0 allows remote authenticated users to read private-document metadata via events.list. The server/routes/api/events/events.ts query treats every event with a null collectionId as global without checking actorId or document ownership, exposing events for private drafts and deleted documents. Any regular member can obtain document IDs, activity timestamps, and some permanently deleted document titles, but not document content directly.

The record

CVE
CVE-2026-28506
Published
Mar 17, 2026
Updated
Mar 17, 2026
Vendor
Outline
Product
Outline
Classifications
CWE-200, T1213
Attack vector
network
Privileges
authenticated

Timeline

How it unfolded

  1. Mar 17, 2026CVE publishedPublication date reported by the CVE source.
  2. Mar 17, 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=< 1.5.0

What conditions does exploitation require?

Attack vectornetwork
Required privilegesauthenticated

What is affected?

Outline · Outlineversion=< 1.5.0

Published CVSS scores

4.3GitHub, Inc.CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/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
Privilegesauthenticated
Known exploitationUnconfirmed
Public exploitPublished

Weakness, pattern, technique

CWE-200Exposure of Sensitive Information to an Unauthorized Actor
T1213Data from Information Repositories

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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