OwnCloud 8.1.8 contains a username enumeration vulnerability that allows remote attackers to discover user accounts by manipulating the share.php endpoint. Attackers can send crafted GET requests to /index.php/core/ajax/share.php with a wildcard search parameter to retrieve comprehensive user information.
https://www.vulncheck.com/advisories/owncloud-username-disclosure
Published: 2026-02-12
Updated: 2026-02-12
Base Score: 10
Vector: CVSS2#AV:N/AC:L/Au:N/C:C/I:C/A:C
Severity: Critical
Base Score: 9.8
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Severity: Critical
Base Score: 5.3
Vector: 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
Severity: Medium