Auth bypass in Makeplane Plane

CVE-2026-105640

Plane is an open-source project management tool. Prior to 1.4.0, Plane trusts email addresses returned by Gitea OAuth and by self-managed GitLab OAuth deployments where email confirmation is disabled, without verifying that the provider authenticated ownership of the address. An attacker can set an OAuth identity's unverified provider email to a victim's address, which Plane matches directly to the victim's existing local account. The attacker can then log in to the victim's Plane account without knowing the victim's password. GitHub, GitLab.com, and Google are not affected because those providers return verified email addresses. This issue is fixed in 1.4.0.

Vulnerability class: Broken Authentication

Published · last modified .

CVSS v3 metric

CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.

EPSS exploit prediction

No EPSS score from FIRST.org yet. New CVEs usually get one within a few days; no score means no signal yet, not low risk. How EPSS works.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2026-105640?
CVE-2026-105640 is a critical-severity vulnerability in Makeplane Plane, classified under Improper Authentication. CVSS score: 9.1/10. Published 2026-10-05.
How severe is CVE-2026-105640?
Critical severity. CVSS v3 base score is 9.1 out of 10.