DEBIAN-CVE-2026-59679
Dashboard / Vulnerabilities / DEBIAN-CVE-2026-59679
Summary:
Details: fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) indexes the per-character encoding[] array using num_chars from the FS_QueryXBitmaps16 reply, but that array was allocated with a size derived from num_extents in the separate FS_QueryXExtents16 reply. The two CARD32 fields are never cross-checked. A malicious or compromised font server can send a small num_extents (e.g. 1) in the extents reply, then a large num_chars (e.g. 100000) in the bitmaps reply. This causes attacker-controlled out-of-bounds heap read and writes.
Affected packages
Package
Name: libxfont
Purl: pkg:deb/debian/libxfont?arch=source&distro=bookworm
Affected ranges
Type: ECOSYSTEM
Events:
Introduced- 0
Fixed -None
Affected versions
1:2.0.6-1
1:2.0.6-1+deb12u1
1:2.0.6-1+hurd.1
1:2.0.6-2
1:2.0.8-1
1:2.0.9-1
Common Vulnerability Scoring System
Attack Vector
Network
Adjacent
Local
Physical
Privileges Required
None
Low
High
User Interaction
None
Required
Scope
Unchanged
Changed
Confidentiality
None
Low
High
Integrity
None
Low
High
Availability
None
Low
High
