Secuno
ENNL
Book demo

CVE-2026-33640

Getoutline Outline vulnerability

9.8 CRITICALPublic exploitEPSS 0.55%
  1. Published26 Mar 2026

Description

Outline is a service that allows for collaborative documentation. Outline implements an Email OTP login flow for users not associated with an Identity Provider. Starting in version 0.86.0 and prior to version 1.6.0, Outline does not invalidate OTP codes based on amount or frequency of invalid submissions, rather it relies on the rate limiter to restrict attempts. Consequently, identified bypasses in the rate limiter permit unrestricted OTP code submissions within the codes lifetime. This allows attackers to perform brute force attacks which enable account takeover. Version 1.6.0 fixes the issue.

CVSS 3.1 breakdown

Attack vectorNetwork
Attack complexityLow
Privileges requiredNone
User interactionNone
ScopeUnchanged
ConfidentialityHigh
IntegrityHigh
AvailabilityHigh
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Affected products

Getoutline Outline≥ 0.86.0 < 1.6.0

Remediation

Fixed in
Getoutline Outline≥ 1.6.0

References

Related CVEs

Recent high-severity vulnerabilities sharing a weakness type.

CVE-2026-1081099.1
PHPNuxBill through 2025.3.20 contains an account takeover vulnerability in the customer…
CVE-2026-1056389.1
Plane is an open-source project management tool. Prior to 1.4.0, Plane's magic-code…
CVE-2026-857349.1
LightRAG provides simple and fast retrieval-augmented generation. Prior to 1.5.5, the…
CVE-2026-62239.4
Improper restriction of excessive authentication attempts vulnerability in Bahçelievler…
CVE-2026-852378.1
A vulnerability in MISP's email-based one-time password (OTP) authentication flow…
CVE-2026-786559.1
Punk::Plugin::TOTP versions before 0.05 for Perl allow the second-factor attempt limit…

Frequently asked

Is CVE-2026-33640 being actively exploited?

CVE-2026-33640 is not in the CISA KEV catalog. A public exploit reference exists, so treat it as exploitable. Its EPSS exploit probability is 0.55%.

How severe is CVE-2026-33640?

CVE-2026-33640 has a CVSS 3.1 base score of 9.8, rated critical. EPSS estimates a 0.55% probability of exploitation.

Which products are affected by CVE-2026-33640?

Affected products include Getoutline Outline.

How do I fix CVE-2026-33640?

Upgrade affected software to a fixed version, for example Getoutline Outline 1.6.0 or later, then confirm no affected versions remain in your inventory.

How Secuno handles this

Secuno correlates vulnerabilities like CVE-2026-33640 against the real software inventory on every managed device, as each hourly inventory arrives. Rather than a static severity, each match is scored in context: exploit availability, EPSS, the asset's exposure, and business criticality decide where it lands in the queue. If an affected version is present anywhere across your portfolio, it surfaces automatically with a prioritised remediation path.

See how prioritisation worksBook a demo

Get Patch this first every Monday

Five vulnerabilities that matter this week, ranked on real exploitation. Plain language, one email, no spam.

You can unsubscribe with one click from every issue. We handle your details as described in our privacy policy.

Data from the NVD, CISA KEV catalog and FIRST EPSS. CVSS 3.1 base score shown where available.