Vulnerability · Published Sep 15, 2026 · Assigned by VulnCheck

CVE-2026-91972Vikunja before 2.6.0 Authentication Bypass via Unthrottled API

High 7.5

In plain English

A high-severity security flaw in vikunja from go-vikunja. Proof-of-concept exploit code is public. The chance it is exploited in the next 30 days is estimated at 0.6% (higher than 51% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.

Severity (CVSS 3.1)7.5High

Exploit odds (30 days)0.6%top 49.5% of all CVEs

Exploited in the wildNo reportsCISA SSVC: poc

Attack toolingNoneno public tooling known

Official description

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.

Affected packages & fixed versions

Ecosystem	Package	Fixed in	Advisory
Go	code.vikunja.io/api	2.6.0	GHSA-6rvj-qwjf-3m4q
Go	code.vikunja.io/api	no fix listed	GO-2026-6721

Affected products (as reported)

Vendor	Product	Versions
go-vikunja	vikunja	0 – before 2.6.0

Weakness: CWE-307 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N

References

GitHub Security Advisory (GHSA-6rvj-qwjf-3m4q) vendor-advisory
VulnCheck Advisory: Vikunja before 2.6.0 Authentication Bypass via Unthrottled API third-party-advisory