Security update for libXfont2

Security update for libXfont2

Security update for libXfont2

Important: libXfont2 security update

Important: libXfont2 security update

Important: libXfont2 security update

ELSA-2026-55448: libXfont2 security update (IMPORTANT)

ELSA-2026-55447: libXfont2 security update (IMPORTANT)

ELSA-2026-55446: libXfont2 security update (IMPORTANT)

[Font Server Client encoding Out-Of-Bounds Read/Write]

A flaw was found in the libXfont2 font-server client. A remote attacker, by operating a malicious font server, could exploit an out-of-bounds read/write vulnerability. This occurs because the client incorrectly handles font data, leading to an out-of-bounds memory access. This can lead to privilege escalation if the X server runs with root privileges, or a denial of service (crash) if it runs as an unprivileged user.

[Font Server Client encoding Out-Of-Bounds Read/Write]

[Font Server Client Cumulative Glyph Data Heap Buffer Overflow]

A flaw was found in the libXfont2 font-server client. This heap buffer overflow vulnerability allows a malicious font server to send specially crafted glyph data. The fs_read_glyphs() function fails to properly validate the total size of the incoming data, leading to an overwrite of memory beyond the intended buffer. If the X server runs as a privileged user, this could result in privilege escalation, allowing an attacker to gain higher access. If the X server runs as an unprivileged user, it could lead to a denial of service, causing the system to crash.

[Font Server Client Cumulative Glyph Data Heap Buffer Overflow]