What is CVE-2026-43890?

CVE-2026-43890 is a high-severity vulnerability in Outline, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 7.7/10. Published 2026-05-11.

How severe is CVE-2026-43890?

High severity. CVSS v3 base score is 7.7 out of 10.

Auth bypass in Outline

CVE-2026-43890

Outline is a service that allows for collaborative documentation. From 0.84.0 to 1.7.0, the subscriptions.create API endpoint in server/routes/api/subscriptions/subscriptions.ts exhibits a broken authorization pattern. When both collection…

Vulnerability class: IDOR (Insecure Direct Object Reference)

EPSS: 0.000 (9.5th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.7 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:C/C:H/I:N/A:N.

Affected products

Outline — versions >= 0.82.1, < 1.7.1

Weakness classification (CWE)

CWE-639 — Authorization Bypass Through User-Controlled Key

References

security-advisories@github.com (x_refsource_CONFIRM)

Frequently asked questions

What is CVE-2026-43890?: CVE-2026-43890 is a high-severity vulnerability in Outline, classified under Authorization Bypass Through User-Controlled Key. CVSS score: 7.7/10. Published 2026-05-11.
How severe is CVE-2026-43890?: High severity. CVSS v3 base score is 7.7 out of 10.