What is the CVSS score of CVE-2026-43886?

CVE-2026-43886 has a CVSS 3.1 base score of 8.2 (High). CVSS vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N. EPSS exploitation probability: 0.0%.

Outline CVE-2026-43886

Q: Which versions of Outline are affected by CVE-2026-43886?

Outline versions 0.84.0-1.6.1 contain an OAuth scope validation flaw with publicly available exploit code that allows registered OAuth clients to escalate from read-only permissions to full…. A patch is available.

Q: How to fix or mitigate CVE-2026-43886?

Within 24 hours, identify all Outline instances in your environment and confirm affected versions (0.84.0-1.6.1), then inventory active OAuth integrations and their authorization scopes. Within 7 days, apply the vendor-released patch to all affected instances and conduct an audit of recent OAuth token activity for evidence of scope escalation attempts. Within 30 days, complete a comprehensive OAuth application authorization review, revoke any high-risk integrations, and implement continuous monitoring for abnormal token scope elevation patterns.

EUVD-2026-29330 HIGH

Improper Privilege Management (CWE-269)

2026-05-11 GitHub_M

Privilege Escalation Outline

8.2

CVSS 3.1 · GitHub Advisory

View

Vulnerability Assessment

Weakness

CWE

CWE-269

OWASP Top 10:2025

A06:2025 - Insecure Design

ASVS 5.0

V8 - Authorization Least privilege enforcement

MITRE ATT&CK

1 technique across 1 tactic: Privilege Escalation

The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up.

This Week Schedule remediation this week. Why: HIGH severity (CVSS 7.0-8.9).

Patch available 0.0% exploitation probability (EPSS)

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AnalysisAIv1 – Jul 23, 2026

Privilege escalation in Outline (the collaborative wiki/knowledge-base) versions 0.84.0 through 1.6.1 lets a malicious OAuth client smuggle the wildcard '*' scope by requesting a mixed scope string such as 'read *', turning a token the user believes is read-only into one with full write, delete, and admin API access. The flaw is a logic error in OAuthInterface.validateScope(), which uses Array.some() so the whole requested scope set passes validation as long as one element is valid. Publicly available exploit code exists (SSVC: PoC), but there is no evidence of active exploitation and EPSS is very low at 0.03% (8th percentile).

Affected VersionsENISA

outline 0.84.0, < 1.7.0

Affected Packages

euvd outline_0_84_0 fix: 1.7.0

Source: OSV (Open Source Vulnerabilities)

Affects your stack

Affects 1 package in euvd

Checking this CVE against your own stacks and servers is part of the Basic plan and up.

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Exploit and PoC references, threat intelligence from 22 sources

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Severity by source

GitHub Advisory PRIMARY 8.2 HIGH

AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:H/A:N

Primary rating from GitHub Advisory · only source for this CVE.

CVSS VectorGitHub Advisory

Attack Vector

Network

Attack Complexity

Low

Privileges Required

None

User Interaction

Required

Scope

Changed

Confidentiality

Low

Integrity

High

Availability

None

Lifecycle Timeline

Patch available

May 11, 2026 - 23:03 EUVD

CVE Published

May 11, 2026 - 21:06 nvd

HIGH 8.2

DescriptionGitHub Advisory

Outline is a service that allows for collaborative documentation. From 0.84.0 to 1.6.1, a logic error in OAuthInterface.validateScope() uses Array.some() to validate requested OAuth scopes, causing the function to accept the entire scope array if any single scope is valid. An attacker can smuggle the wildcard * scope by requesting scope=read *, escalating a read-only OAuth token to full unrestricted API access including write, delete, and admin operations. This vulnerability is fixed in 1.7.0.

Executive ViewAI

Why It Matters

Outline versions 0.84.0-1.6.1 contain an OAuth scope validation flaw with publicly available exploit code that allows registered OAuth clients to escalate from read-only permissions to full administrative access over wiki data and APIs. Organizations using Outline with OAuth integrations face risk of unauthorized data modification, deletion, and administrative takeover by malicious external OAuth applications.

Recommended Action

Within 24 hours, identify all Outline instances in your environment and confirm affected versions (0.84.0-1.6.1), then inventory active OAuth integrations and their authorization scopes. Within 7 days, apply the vendor-released patch to all affected instances and conduct an audit of recent OAuth token activity for evidence of scope escalation attempts. Within 30 days, complete a comprehensive OAuth application authorization review, revoke any high-risk integrations, and implement continuous monitoring for abnormal token scope elevation patterns.

Business Impact: High

Compensating Controls

Apply vendor patch.

Threat Intelligence Overview

EPSS Score

0.0%

Top 92% exploitable

Data Quality

6 sources

Confidence: High

EUVD

NVD

CVE.org

EPSS

Vulnrichment

GitHub

How this decision was reached

The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.

SignalValue

Severity HIGH

CISA KEV No

Public POC No

EPSS 0.0%

Patch available Yes

Active threat No

Deciding rule

HIGH severity (CVSS 7.0-8.9)

What every action level means

Emergency Immediate action required. Criteria: CRITICAL + in CISA KEV (actively exploited) without patch, OR CRITICAL + EPSS > 30% without patch, OR CRITICAL + active threat signals without patch.

Act Now Prioritize within 24-48h. Criteria: in KEV with patch available, OR CRITICAL + public POC, OR HIGH + EPSS > 10%, OR CRITICAL + active threat, OR any CRITICAL severity.

This Week Schedule remediation this week. Criteria: HIGH severity (CVSS 7.0-8.9). Patch within normal change window.

This Month Plan within 30 days. Criteria: MEDIUM severity (CVSS 4.0-6.9), lower exploitation probability. Include in regular patch cycle.

Monitor Track and reassess. Criteria: LOW severity (CVSS 0.1-3.9), minimal exploitation risk. No immediate action needed.

SSVC AssessmentENISA

SSVC Decision

Scheduled

Exploitation

Poc

System Exposure· derived

Open

Automatable

Human Impact

High

Technical Impact

Partial

Priority Score

Low Medium High Critical

KEV: 0

EPSS: 0

CVSS: +41

PoC: 0

Weaponized: 0

Threat intel: 0

Gov advisory: 0

Attack Technique

Privilege Escalation HIGH

Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.