---
id: GHSA-p2vv-wrh8-x466
title: >-
  Duplicate Advisory: Vikunja: CalDAV and feeds BasicAuth endpoints have no rate
  limit, bypassing the anti-brute-force floor on account passwords
summary: >-
  Duplicate Advisory: Vikunja: CalDAV and feeds BasicAuth endpoints have no rate
  limit, bypassing the anti-brute-force floor on account passwords
severity: high
cvss: 7.5
cwe:
  - CWE-307
vendor: api
product: code.vikunja.io/api
ecosystem: go
affected:
  - code.vikunja.io/api <= 2.5.0
published: '2026-09-15'
updated: '2026-10-09'
sourceUpdated: '2026-10-09T20:51:58Z'
source: GHSA
sourceUrl: 'https://github.com/advisories/GHSA-p2vv-wrh8-x466'
references:
  - url: >-
      https://github.com/go-vikunja/vikunja/security/advisories/GHSA-m469-88xx-8rx2
  - url: 'https://nvd.nist.gov/vuln/detail/CVE-2026-91973'
  - url: >-
      https://www.vulncheck.com/advisories/vikunja-before-2.6.0-authentication-bypass-via-caldav-basicauth
  - url: 'https://github.com/advisories/GHSA-p2vv-wrh8-x466'
tags:
  - ghsa
  - go
ingestedAt: '2026-10-09T21:12:42.330Z'
---

## Overview

### Duplicate Advisory
This advisory has been withdrawn because it is a duplicate of GHSA-m469-88xx-8rx2. This link is maintained to preserve external references.

### Original Description
Vikunja before 2.6.0 contains an authentication bypass vulnerability in CalDAV BasicAuth endpoints that lack rate limiting protection. Remote unauthenticated attackers can issue unbounded credential-guessing requests against /dav, /.well-known, and /feeds routes to bypass the instance's anti-brute-force controls and compromise password-only accounts.

## Affected packages

- `code.vikunja.io/api <= 2.5.0`

## Remediation

Refer to the advisory for the patched release.