CVE-2026-59679: fs_read_glyphs() heap OOB read/write via encoding array index mismatch in libXfont2

Overview

Severity

Critical (CVSS 9)

CVSS Vector

CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H

Exploit Status

Not Exploited

Patch Tuesday

2026-Sep

Released

2026-09-17

EPSS Score

0.41% (percentile: 34.9%)

Affected Products (1)

Other

• 21880-17084

Security Updates (1)

• Security Update

Revision History

• 2026-09-17: Information published.