An out-of-bounds read in libXi's XI2 class parsing via size_classes() and copy_classes() in libXi before 1.8.4 could be used by malicous servers to… (CVE-2026-93542)

CVE-2026-93542 describes an out-of-bounds read vulnerability in the libXi library, specifically in the XI2 class parsing functions size_classes() and copy_classes(). This vulnerability affects libXi versions prior to 1.8.4. An attacker controlling a malicious server could exploit this flaw to crash the X client by triggering the out-of-bounds read, causing a denial of service. The vulnerability has a CVSS 3.1 base score of 6.5 (AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H). There is no indication of confidentiality or integrity impact, only availability is affected. No vendor advisory or patch links are provided in the input, so patch status is not confirmed here.

The primary impact is denial of service due to a crash of the X client when processing maliciously crafted XI2 class data from a server. There is no reported impact on confidentiality or integrity. No known active exploitation has been reported.

Patch status is not yet confirmed — check the vendor advisory for current remediation guidance. Users should monitor for updates to libXi and apply official patches once available. Until patched, avoid connecting to untrusted or malicious X servers to reduce risk of exploitation.