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TI-2026-22768 Aliases CVE-2026-28506

Outline's Information Disclosure in Activity Logs allows User Enumeration of Private Drafts

Priority MEDIUM 53CWE-200Published · Updated

Key facts

Attack vector
Network
Privileges required
Low
User interaction
None
Attack complexity
Low
Impact type
Information disclosure
Confidentiality · integrity · availability
Low · None · None
Fix status
Fixed

Attack profile from CVSS 3.1 · CNA. Fix status from CNA. Impact type from CWE-200.

Summary

Outline is a service that allows for collaborative documentation. Prior to 1.5.0, the events.list API endpoint, used for retrieving activity logs, contains a logic flaw in its filtering mechanism. It allows any authenticated user to retrieve activity events associated with documents that have no collection (e.g., Private Drafts, Deleted Documents), regardless of the user's actual permissions on those documents. While the document content is not directly exposed, this vulnerability leaks sensitive metadata (such as Document IDs, user activity timestamps, and in some specific cases like the Document Title of Permanent Delete). Crucially, leaking valid Document IDs of deleted drafts removes the protection of UUID randomness, making High-severity IDOR attacks (such as the one identified in documents.restore) trivially exploitable by lowering the attack complexity. Version 1.5.0 fixes the issue.

Why it matters now

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.00243 15th percentileScored 2026-11-07
Public exploit Yes 1 exploit referenceTagged by NVD
Fix Fixed outline (outline): 1.5.0

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
Poc
Automatable
No
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
outlineoutlinebefore 1.5.01.5.0Patch availableCNA
  • outline Vendoroutline Affected before 1.5.0 Fixed in 1.5.0 Patch available CNA

CPE configurations NVD · 1

CPEVersionsRoleVendor
cpe:2.3:a:getoutline:outline:*:*:*:*:*:*:*:*before 1.5.0Vulnerableoutline
  • cpe:2.3:a:getoutline:outline:*:*:*:*:*:*:*:* Versions before 1.5.0 Vulnerable ·outline

Remediation

  • Fix · CNA outline (outline) Fixed in 1.5.0

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-28506

References

Exploit 1

  • TI-2026-26021 Outline has a rate limit bypass that allows brute force of email login OTP CVSS 4.0CRITICAL 9.1
  • TI-2026-20086 Outline's IDOR allows unauthorized viewing and seizing of private deleted drafts CVSS 3.1HIGH 8.8
  • TI-2024-25167 An issue in Outline <= v0.76.1 allows attackers to execute a session hijacking attack via… CVSS 3.1HIGH 8.8
  • TI-2026-30168 Outline has IDOR in document share creation that allows unauthorized access to private documents across workspaces CVSS 3.1HIGH 7.7
  • TI-2024-27038 Stored Cross-site Scripting (XSS) vulnerability in Outline editor CVSS 3.1HIGH 7.3
  • TI-2026-32586 Outline: Slack OAuth state can link a victim Outline account to an attacker Slack identity CVSS 3.1MEDIUM 6.5
See all 14 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences