Quick answer
Direct answer
Risk scores
| CVSS metric | What it means |
|---|---|
| Attack vector (AV:N) | Network: reachable remotely |
| Attack complexity (AC:H) | High complexity |
| Privileges required (PR:N) | No privileges required |
| User interaction (UI:N) | No user interaction |
| Scope (S:U) | Scope unchanged |
| Confidentiality (C:H) | High confidentiality impact |
| Integrity (I:H) | High integrity impact |
| Availability (A:N) | No availability impact |
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:N
About Vikunja
CVE-2026-34727 affects Vikunja, a product from Vikunja. Before acting, confirm where Vikunja runs in your estate, who owns it and whether it is reachable from the internet, because exposure decides real risk more than the score alone.
What the flaw is
In plain terms: Vikunja is an open-source self-hosted task management platform. Prior to 2.3.0, the OIDC callback handler issues a full JWT token without checking whether the matched user has TOTP two-factor authentication enabled. When a local user with TOTP enrolled is matched via the OIDC email fallback mechanism, the second factor is completely skipped. This vulnerability is fixed in 2.3.0.
The weakness class is Improper Authentication. The software does not properly prove who a user is.
Based on its CVSS vector, the flaw can be reached over the network, needs no login, and needs no user interaction. Apply the vendor fix and confirm exposure on internet facing and business critical assets first.
Affected versions and timeline
| Field | Detail |
|---|---|
| Product | Vikunja |
| Affected versions | Vikunja before 2.3.0 |
| Published | Apr 10, 2026 |
| Last modified | Jun 17, 2026 |
| Added to CISA KEV | Not listed |
| Assigning CNA | security-advisories@github.com |
How to detect it
- Inventory every instance of Vikunja and record the running version against the affected range above.
- Check external attack surface scans for internet facing instances of the component.
- Review logs on affected systems for unusual requests, errors or new processes around the vulnerable function.
- Confirm with an authenticated vulnerability scan once your scanner has a check for this CVE.
How to fix it
- Apply the fixed version of Vikunja named in the vendor advisory.
- If patching must wait, restrict network access to the affected service and put it behind authentication or a web application firewall rule.
- Rescan after the change to prove the exposure is gone, then close the ticket.
CTEM action plan
| CTEM stage | What to do for this CVE |
|---|---|
| Scope | Add every business service that depends on Vikunja to the current CTEM cycle. |
| Discover | Find all instances, including shadow and cloud deployments, and record versions and exposure. |
| Prioritize | Rank using EPSS and CVSS together with asset exposure and business impact. |
| Validate | Confirm the flaw is reachable and exploitable in your environment and that compensating controls work. |
| Mobilize | Assign the fix to the asset owner with a due date matched to the priority, then verify closure. |
CWE References
- CWE-287: Improper Authentication More CVEs with this weakness
Technical References
Frequently asked questions
Related CVEs
Vikunja is an open-source self-hosted task management platform. Starting in version 0.18.0 and prior to version 2.2.1, when a user account is disabled or locked, the status check is only enforced on the local login and JWT token refresh paths. Three other authentication paths — API tokens, CalDAV basic auth, and OpenID Connect — do not verify user status, allowing disabled or locked users to continue accessing the API and syncing data. Version 2.2.1 patches the issue.
A remote authentication bypass vulnerability exists in HPE AutoPass License Server (APLS).
Improper authentication in Azure Key Vault allows an unauthorized attacker to elevate privileges over a network.
Dokans Multi-Tenancy Based eCommerce Platform SaaS 3.9.2 allows unauthenticated remote attackers to obtain sensitive application configuration data via direct request to /script/.env file. The exposed file contains Laravel application encryption key (APP_KEY), database credentials, SMTP/SendGrid API credentials, and internal configuration parameters, enabling complete system compromise including authentication bypass via session token forgery, direct database access to all tenant data, and email infrastructure takeover. Due to the multi-tenancy architecture, this vulnerability affects all tenants in the system.
FUXA is a web-based Process Visualization (SCADA/HMI/Dashboard) software. Prior to 1.2.10, an authentication bypass vulnerability in FUXA allows an unauthenticated, remote attacker to gain administrative access via the heartbeat refresh API and execute arbitrary code on the server. This issue has been patched in FUXA version 1.2.10.
The vulnerability exists in BLUVOYIX due to improper authentication in the BLUVOYIX backend APIs. An unauthenticated remote attacker could exploit this vulnerability by sending specially crafted HTTP requests to the vulnerable APIs. Successful exploitation of this vulnerability could allow the attacker to gain full access to customers' data and completely compromise the targeted platform.
Earn your free CTEM certification.
Learn to scope, prioritize, validate and mobilize fixes for CVEs like CVE-2026-34727 with a free CTEM certification.
Beginner / Practitioner / Program Leader
Explore certifications