CVE-2026-91973EPSS p50.4%

CVE-2026-91973CVE-2026-91973

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.

Scoring

CVSS 7.5 ()
VectorCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:N/A:N
EPSS0.67% probability of exploitation · percentile 50.4% · 2026-10-05T12:00:23Z
Last modified2026-09-16
Sourced from NVD + FIRST.org EPSS. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.