Is CVE-2026-43886 exploited in the wild?

No. Junglewise Threat Intelligence has no report of CVE-2026-43886 being exploited in the wild.

How severe is CVE-2026-43886?

High severity, with a CVSS score of 8.2, published 11 May 2026.

Which products and versions are affected?

Outline Outline 0.84.0 to 1.6.1.

Is there a fix for CVE-2026-43886?

A patch was published on 2026-05-11: Fix confirmed in version 1.7.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.

How is CVE-2026-43886 attacked?

It is attacked over the network, in a network appliance.

Am I affected by CVE-2026-43886?

Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

CVE-2026-43886: Outline privilege escalation via OAuth scope wildcard smuggling

CVE-2026-43886 · Severity: high · CVSS 8.2 · Published 2026-05-11

Outline, a collaborative documentation platform, contains a security flaw in how it handles third-party application permissions. An attacker can trick the system into granting full administrative access to an account even when only limited "read-only" access was requested. This allows an unauthorized user to view, modify, or delete all corporate documents, manage users, and change team settings, potentially leading to a total compromise of the organization's documentation and internal knowledge base.

Quick answers

Is CVE-2026-43886 exploited in the wild?: No. Junglewise Threat Intelligence has no report of CVE-2026-43886 being exploited in the wild.
How severe is CVE-2026-43886?: High severity, with a CVSS score of 8.2, published 11 May 2026.
Which products and versions are affected?: Outline Outline 0.84.0 to 1.6.1.
Is there a fix for CVE-2026-43886?: A patch was published on 2026-05-11: Fix confirmed in version 1.7.0 Junglewise finds every place you run it, drafts the upgrade and applies it once you approve.
How is CVE-2026-43886 attacked?: It is attacked over the network, in a network appliance.
Am I affected by CVE-2026-43886?: Check whether anything you run is named in the advisory. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

Technical details

A logic error exists in the `OAuthInterface.validateScope()` function within Outline. The function uses the JavaScript `Array.some()` method to validate requested OAuth scopes but incorrectly returns the entire requested scope array if any single scope in the list is valid. An attacker can exploit this by requesting a legitimate scope alongside a wildcard character (e.g., `scope=read *`). Because "read" is valid, the validator returns the full array including the wildcard. Subsequent checks in `AuthenticationHelper.canAccess()` interpret the wildcard as granting unrestricted access to all API endpoints, including write, delete, and administrative operations. The vulnerability is fixed in version 1.7.0.

Affected products

Outline Outline 0.84.0 to 1.6.1

Timeline

2026-05-07: advisory: GitHub Security Advisory published by maintainers
2026-05-11: disclosed: CVE published to NVD
2026-05-11: patched: Fix confirmed in version 1.7.0

References

https://github.com/outline/outline/security/advisories/GHSA-7732-6qrg-wjf4

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