AbuseFilter exposes information that is intended to be access‑controlled, due to a misuse of the ::userCanBitfield function. The flaw allows users to obtain data about which actions or permissions are held by other users, violating confidentiality and potentially aiding adversaries in planning further attacks. The primary impact is the disclosure of privileged information, without any direct code execution or denial of service.

Wikimedia Foundation AbuseFilter is affected. The vulnerability exists in versions prior to 1.43.7, 1.44.4, and 1.45.2. Any installation running these versions can potentially leak access‑controlled information.

The CVSS score of 2.1 indicates a low overall risk. The EPSS score is unavailable, and the vulnerability is not currently listed in the CISA KEV catalog. Attack vectors are inferred from the description to be via normal use of the AbuseFilter API, which is generally accessible to authenticated users. An attacker could request filter data and receive additional user permission details. Although exploitation is unlikely to result in further privileges, the leaked information may be valuable for reconnaissance.