---
id: CVE-2026-91972
title: >-
  Vikunja versions before 2.6.0 fail to apply rate limiting to /api/v2 public
  authentication endpoints including login, register, password-reset, and OAuth
  token routes
summary: >-
  Vikunja versions before 2.6.0 fail to apply rate limiting to /api/v2 public
  authentication endpoints including login, register, password-reset, and OAuth
  token routes. Remote unauthenticated attackers can perform unbounded
  credential gue…
severity: high
cvss: 7.5
cvssVector: 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N'
cwe:
  - CWE-307
vendor: go-vikunja
product: vikunja
affected:
  - vikunja < 2.6.0
published: '2026-09-15'
updated: '2026-09-17'
sourceUpdated: '2026-09-17T16:18:32.093'
source: NVD
sourceUrl: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91972'
references:
  - url: >-
      https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6rvj-qwjf-3m4q
    label: disclosure@vulncheck.com
  - url: >-
      https://www.vulncheck.com/advisories/vikunja-before-2.6.0-authentication-bypass-via-unthrottled-api
    label: disclosure@vulncheck.com
  - url: >-
      https://github.com/go-vikunja/vikunja/security/advisories/GHSA-6rvj-qwjf-3m4q
    label: 134c704f-9b21-4f2e-91b3-4a467353bcc0
tags:
  - nvd
  - cve.org
  - exploit-available
exploitAvailable: true
ssvc:
  exploitation: poc
  automatable: 'yes'
  technicalImpact: partial
  timestamp: '2026-09-17T15:11:53.582933Z'
epss: 0.00498
epssPercentile: 0.41761
ingestedAt: '2026-09-15T15:39:12.912Z'
---

## Overview

Vikunja versions before 2.6.0 fail to apply rate limiting to /api/v2 public authentication endpoints including login, register, password-reset, and OAuth token routes. Remote unauthenticated attackers can perform unbounded credential guessing, account enumeration, and password-reset flooding attacks without throttling restrictions.

## Remediation

Refer to the linked advisories for vendor-supplied fixes and affected version ranges.