# CVE-2026-62367: Vikunja: OIDC email-fallback account linking ignores email_verified, enabling local-account takeover

> Attackers can take over local accounts via OIDC email fallback if enabled, bypassing password checks and email verification.

- **Severity:** High 7.5 (`CVSS:4.0/AV:L/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Local or same network only
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 9 Oct 2026
- **Updated:** 13 Oct 2026
- **Also known as:** GHSA-xv7q-fvmc-jx96, GO-2026-6758

## What is CVE-2026-62367?

CVE-2026-62367 is a high-severity authentication bypass vulnerability in go-vikunja vikunja, published on 9 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.

### Official description

Vikunja is an open-source self-hosted task management platform. In versions 1.0.0 through 2.3.0, when an administrator enables the per-provider `emailfallback` option on an OpenID Connect provider, Vikunja links an SSO login to a pre-existing local (username+password) account using only the `email` claim from the IdP. The fallback never checks an `email_verified` (or Microsoft `xms_edov`) signal and never requires the matched account's password. An attacker who can obtain a token from the configured issuer carrying a victim's email logs in as that victim with a full session, with no consent or interaction from the victim. Version 2.4.0 fixes the issue.

Weakness: CWE-345 (Insufficient Verification of Data Authenticity), CWE-290 (Authentication Bypass by Spoofing), CWE-287 (Improper Authentication)

## Which versions are affected by CVE-2026-62367?

3 open source packages ship an affected version, including code.vikunja.io/api.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `code.vikunja.io/api` | Go | All versions | None |
| `code.vikunja.io/api` | Go | From 1.0.0 | 2.4.0 |
| `code.vikunja.io/api` | Go | From 1.0.0 | 2.4.0 |

## How do I fix CVE-2026-62367?

Upgrade code.vikunja.io/api to 2.4.0 or later.

## Is CVE-2026-62367 being exploited?

There is no known exploitation of CVE-2026-62367 in the wild and no public exploit code.

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-62367 and fix it if it is affected.

What it is: CVE-2026-62367 is a high-severity authentication bypass vulnerability in go-vikunja vikunja, published on 9 Oct 2026. It can only be exploited from the same machine or local network, with no action from the victim.
Exploitation: There is no known exploitation of CVE-2026-62367 in the wild and no public exploit code.

Affected packages and fixed versions:
- code.vikunja.io/api (Go): affected all versions; no fix listed
- code.vikunja.io/api (Go): affected from 1.0.0; fixed in 2.4.0
- code.vikunja.io/api (Go): affected from 1.0.0; fixed in 2.4.0

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-2026-62367/ (Markdown: https://insights.sbomify.com/CVE-2026-62367/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-62367
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-62367
- OSV: https://osv.dev/vulnerability/CVE-2026-62367

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-62367/
Summaries are generated and may contain mistakes; the official description above is the record.