# CVE-2026-105640: Plane: Account Takeover via Unverified OAuth Email Match (Gitea, self-managed GitLab)

> Attackers can take over accounts by exploiting unverified email matching in Gitea or self-managed GitLab OAuth integrations.

- **Severity:** Critical 9.1 (`CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** No
- **Published:** 5 Oct 2026
- **Updated:** 5 Oct 2026
- **Also known as:** GHSA-7j95-vh8g-f365

## What is CVE-2026-105640?

CVE-2026-105640 is a critical authentication bypass vulnerability in makeplane plane, published on 5 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

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.

Weakness: CWE-290 (Authentication Bypass by Spoofing), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-105640?


## How do I fix CVE-2026-105640?

No fix has been published for CVE-2026-105640 yet. Limit exposure of the affected software until one is available.

## Is CVE-2026-105640 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105640 exists.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-105640 and fix it if it is affected.

What it is: CVE-2026-105640 is a critical authentication bypass vulnerability in makeplane plane, published on 5 Oct 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.
Exploitation: It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-105640 exists.

Affected product: makeplane plane. No package-level version data is available, so check the vendor advisory linked from the reference page.

Task:
1. Search the dependency manifests and lockfiles (for example package.json, package-lock.json, requirements.txt, poetry.lock, uv.lock, pom.xml, build.gradle, go.mod, Cargo.lock, Gemfile.lock) and any Dockerfiles for the affected packages, including transitive dependencies.
2. If an affected version is in use, upgrade it to the fixed version for its release line with the project's package manager, so the lockfile is regenerated. Prefer the smallest upgrade that fixes it.
3. If there is no fix, or the upgrade would break the build, do not guess: explain the risk and the safest workaround instead.
4. Run the tests and summarise what changed and why.
5. If nothing in the project is affected, say so and change nothing.

Reference: https://insights.sbomify.com/CVE-2026-105640/ (Markdown: https://insights.sbomify.com/CVE-2026-105640/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-105640
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-105640
- OSV: https://osv.dev/vulnerability/CVE-2026-105640

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-105640/
Summaries are generated and may contain mistakes; the official description above is the record.