CVE-2026-91981CWE-200information-disclosure

CVE-2026-91981

Medium · published September 15, 2026

CVSS v3.1
4.3
EPSS
0%
Percentile
22.0
In the wild
Unconfirmed
What it is

Vikunja versions before 2.6.0 fail to properly validate link-share tokens in the v2 API user search endpoints. Attackers with a read-only share link can enumerate project users via the projects endpoint and confirm arbitrary usernames exist via the global search endpoint.

The record
Technical detail
CVSS v3.1
4.3 · MEDIUM
Vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N
CVSS v4.0
5.3 · CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N
EPSS
0.00306 · 22.0th percentile
Weakness
CWE-200 · Exposure of Sensitive Information to an Unauthorized Actor
Published
2026-09-15T20:17Z
References (3)
https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vfxw-3x8p-2vjr · [email protected]https://www.vulncheck.com/advisories/vikunja-before-2.6.0-user-enumeration-via-v2-api · [email protected]https://github.com/go-vikunja/vikunja/security/advisories/GHSA-vfxw-3x8p-2vjr · 134c704f-9b21-4f2e-91b3-4a467353bcc0
EPSS history
Timeline
  • 17 SEP 03:33Z
    EPSS moved — → 0%
    epss
  • 15 SEP 15:18Z
    Vikunja before 2.6.0 User Enumeration via v2 API
    cvelistv5