BuddyPress 14.4.0 contains a regular expression injection vulnerability in the activity mention resolver that, when username compatibility mode is enabled, allows attackers to manipulate a REGEXP database clause by crafting mention names containing regex metacharacters. Attackers can submit @mentions whose metacharacters pass through esc_sql unescaped and are inserted into an unprepared REGEXP query against the users table, enabling boolean-based inference of usernames and denial of service through catastrophic backtracking.
https://www.vulncheck.com/advisories/buddypress-regexp-injection-via-mention-username-resolution
Published: 2026-06-10
Updated: 2026-06-10
Base Score: 7.5
Vector: CVSS2#AV:N/AC:L/Au:S/C:P/I:N/A:C
Severity: High
Base Score: 7.1
Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:H
Severity: High
Base Score: 7.1
Vector: CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
Severity: High