# CVE-2026-33315: Vikunja has a 2FA Bypass via Caldav Basic Auth

> Attackers can bypass two-factor authentication on Vikunja accounts via the CalDAV endpoint to access protected project information.

- **Severity:** Medium 6.9 (`CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N`)
- **Exploited in the wild:** Not known
- **Login needed:** Not needed
- **Attackable:** Over the internet
- **Victim action needed:** Not needed
- **Fix available:** Yes
- **Published:** 24 Mar 2026
- **Updated:** 24 Mar 2026
- **Also known as:** GHSA-47cr-f226-r4pq, GO-2026-4794

## What is CVE-2026-33315?

CVE-2026-33315 is a medium-severity authentication bypass vulnerability in go-vikunja vikunja, published on 24 Mar 2026. An attacker can exploit it over the internet without logging in, with no action from the victim.

### Official description

Vikunja is an open-source self-hosted task management platform. Prior to version 2.2.0, the Caldav endpoint allows login using Basic Authentication, which in turn allows users to bypass the TOTP on 2FA-enabled accounts. The user can then access standard project information that would normally be protected behind 2FA (if enabled), such as project name, description, etc. Version 2.2.0 patches the issue.

Weakness: CWE-288 (Authentication Bypass Using an Alternate Path or Channel)

## Which versions are affected by CVE-2026-33315?

3 open source packages ship an affected version, including code.vikunja.io/api. It affects 1 product.


| Package | Ecosystem | Affected | Fixed in |
| --- | --- | --- | --- |
| `code.vikunja.io/api` | Go | All versions | None |
| `code.vikunja.io/api` | Go | All versions to 2.1.0 | None |
| `code.vikunja.io/api` | Go | All versions to 2.1.0 | None |

Products: Vikunja Vikunja.

## How do I fix CVE-2026-33315?

Upgrade to a fixed version.

## Is CVE-2026-33315 being exploited?

It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-33315 exists.

## Other vulnerabilities in go-vikunja vikunja

- [CVE-2026-28268](https://insights.sbomify.com/CVE-2026-28268/): Vikunja Vulnerable to Account Takeover via Password Reset Token Reuse (critical 9.8)
- [CVE-2026-27575](https://insights.sbomify.com/CVE-2026-27575/): Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change (critical 9.1)
- [CVE-2026-25935](https://insights.sbomify.com/CVE-2026-25935/): Vikunja Affected by XSS Via Task Preview (high 8.6)
- [CVE-2026-35595](https://insights.sbomify.com/CVE-2026-35595/): Vikunja Affected by Privilege Escalation via Project Reparenting (high 8.3)
- [CVE-2026-33316](https://insights.sbomify.com/CVE-2026-33316/): Vikunja’s Improper Access Control Enables Bypass of Administrator-Imposed Account Disablement (high 8.1)

## Fix prompt for AI coding agents

```text
Check this codebase for CVE-2026-33315 and fix it if it is affected.

What it is: CVE-2026-33315 is a medium-severity authentication bypass vulnerability in go-vikunja vikunja, published on 24 Mar 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-2026-33315 exists.

Affected packages and fixed versions:
- code.vikunja.io/api (Go): affected all versions; no fix listed
- code.vikunja.io/api (Go): affected all versions up to 2.1.0; no fix listed
- code.vikunja.io/api (Go): affected all versions up to 2.1.0; no fix listed

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-2026-33315/ (Markdown: https://insights.sbomify.com/CVE-2026-33315/index.md)
```

## Sources

- CVE record: https://www.cve.org/CVERecord?id=CVE-2026-33315
- NVD: https://nvd.nist.gov/vuln/detail/CVE-2026-33315
- OSV: https://osv.dev/vulnerability/CVE-2026-33315

---
From sbomify Insights: https://insights.sbomify.com/CVE-2026-33315/
Summaries are generated and may contain mistakes; the official description above is the record.