CVE-2026-35597 Vikunja Affected by TOTP Brute-Force Due to Non-Functional Account Lockout
Attackers can bypass TOTP account lockout protections to perform unlimited brute-force attacks against user accounts in Vikunja.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2026-35597?
CVE-2026-35597 is a medium-severity vulnerability in go-vikunja vikunja, published on 10 Apr 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 2.3.0, the TOTP failed-attempt lockout mechanism is non-functional due to a database transaction handling bug. When a TOTP validation fails, the login handler in pkg/routes/api/v1/login.go calls HandleFailedTOTPAuth and then unconditionally rolls back. HandleFailedTOTPAuth in pkg/user/totp.go uses an in-memory counter (key-value store) to track failed attempts. When the counter reaches 10, it calls user.SetStatus(s, StatusAccountLocked) on the same database session s. Because the login handler always rolls back after a TOTP failure, the StatusAccountLocked write is undone. The in-memory counter correctly increments past 10, so the lockout code executes on every subsequent attempt, but the database write is rolled back every time. This allows unlimited brute-force attempts against TOTP codes. This vulnerability is fixed in 2.3.0.
Weakness: CWE-307
Which versions are affected by CVE-2026-35597?
3 open source packages ship an affected version, including code.vikunja.io/api. It affects 1 product.
| Package | Affected | Fixed in |
|---|---|---|
code.vikunja.io/api Go | All versions | None |
code.vikunja.io/api Go | All versions | 2.3.0 |
code.vikunja.io/api Go | All versions | 2.3.0 |
Products include Vikunja Vikunja.
How do I fix CVE-2026-35597?
Upgrade code.vikunja.io/api to 2.3.0 or later.
Is CVE-2026-35597 being exploited?
It is not confirmed as exploited in the wild, but public exploit code for CVE-2026-35597 exists.
Other vulnerabilities in go-vikunja vikunja
- CVE-2026-28268 Vikunja Vulnerable to Account Takeover via Password Reset Token Reuse
- CVE-2026-27575 Vijkunja has Weak Password Policy Combined with Persistent Sessions After Password Change
- CVE-2026-25935 Vikunja Affected by XSS Via Task Preview
- CVE-2026-35595 Vikunja Affected by Privilege Escalation via Project Reparenting
- CVE-2026-33316 Vikunja’s Improper Access Control Enables Bypass of Administrator-Imposed Account Disablement
Sources
Also known as GHSA-fgfv-pv97-6cmj, GO-2026-5362.