CVE-2026-59679

Summary

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 Software

VendorProductVersion RangeStatus
SUSEContainer suse/kiosk/tigervnc-x11vnc:1.14-63.8? < 2.0.3-150000.3.6.1affected
SUSEContainer suse/kiosk/xorg:21.1-83.7? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Azure-3P? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-BYOS? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-BYOS-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-BYOS-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-BYOS-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Hardened? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Hardened-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Hardened-BYOS? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Hardened-BYOS-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Hardened-BYOS-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Hardened-BYOS-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Hardened-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAP-Hardened-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAPCAL? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAPCAL-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAPCAL-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP6-SAPCAL-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-Azure-3P? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-BYOS-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-BYOS-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-BYOS-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-GCE-3P? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-Hardened-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-Hardened-BYOS-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-Hardened-BYOS-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-Hardened-BYOS-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAP-Hardened-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAPCAL-Azure? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAPCAL-EC2? < 2.0.3-150000.3.6.1affected
SUSEImage SLES15-SP7-SAPCAL-GCE? < 2.0.3-150000.3.6.1affected
SUSEImage SLES-SAP-Azure? < 2.0.7-160000.5.1affected
SUSEImage SLES-SAP-Azure-3P? < 2.0.7-160000.5.1affected
SUSEImage SLES-SAP-BYOS-Azure? < 2.0.7-160000.5.1affected
SUSEImage SLES-SAP-BYOS-EC2? < 2.0.7-160000.5.1affected
SUSEImage SLES-SAP-BYOS-GCE? < 2.0.7-160000.5.1affected
SUSEImage SLES-SAP-GCE? < 2.0.7-160000.5.1affected
SUSEImage SLES-SAP-GCE-3P? < 2.0.7-160000.5.1affected
SUSEImage SLES-SAPCAL-GCE? < 2.0.7-160000.5.1affected
SUSEImage SLES12-SP5-Azure-SAP-BYOS? < 2.0.3-3.6.1affected
SUSEImage SLES12-SP5-Azure-SAP-On-Demand? < 2.0.3-3.6.1affected
SUSEImage SLES12-SP5-EC2-SAP-BYOS? < 2.0.3-3.6.1affected
SUSEImage SLES12-SP5-EC2-SAP-On-Demand? < 2.0.3-3.6.1affected
SUSEImage SLES12-SP5-GCE-SAP-BYOS? < 2.0.3-3.6.1affected
SUSEImage SLES12-SP5-GCE-SAP-On-Demand? < 2.0.3-3.6.1affected
SUSESUSE Liberty Linux 10? < 2.0.6-5.el10_2.3affected
SUSESUSE Liberty Linux 10? < 2.0.6-5.el10_2.3affected
SUSESUSE Liberty Linux 8? < 2.0.3-2.el8_10.3affected
SUSESUSE Liberty Linux 8? < 2.0.3-2.el8_10.3affected
SUSESUSE Liberty Linux 9? < 2.0.3-12.el9_8.3affected
SUSESUSE Liberty Linux 9? < 2.0.3-12.el9_8.3affected
SUSESUSE Linux Enterprise Desktop 15 SP7? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Desktop 15 SP7? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Module for Basesystem 15 SP7? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Module for Basesystem 15 SP7? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 15 SP7? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 15 SP7? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server for SAP Applications 15 SP7? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server for SAP Applications 15 SP7? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise High Performance Computing 15 SP4-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise High Performance Computing 15 SP4-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise High Performance Computing 15 SP5-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise High Performance Computing 15 SP5-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 12 SP5-LTSS? < 2.0.3-3.6.1affected
SUSESUSE Linux Enterprise Server 15 SP4-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 15 SP4-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 15 SP5-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 15 SP5-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 15 SP6-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 15 SP6-LTSS? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server 16.0? < 2.0.7-160000.5.1affected
SUSESUSE Linux Enterprise Server 16.0? < 2.0.7-160000.5.1affected
SUSESUSE Linux Enterprise Server for SAP applications 16.0? < 2.0.7-160000.5.1affected
SUSESUSE Linux Enterprise Server for SAP applications 16.0? < 2.0.7-160000.5.1affected
SUSESUSE Linux Enterprise Server LTSS Extended Security 12 SP5? < 2.0.3-3.6.1affected
SUSESUSE Linux Enterprise Server for SAP Applications 15 SP4? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server for SAP Applications 15 SP4? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server for SAP Applications 15 SP5? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server for SAP Applications 15 SP5? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server for SAP Applications 15 SP6? < 2.0.3-150000.3.6.1affected
SUSESUSE Linux Enterprise Server for SAP Applications 15 SP6? < 2.0.3-150000.3.6.1affected
SUSESUSE Manager Proxy LTS 4.3? < 2.0.3-150000.3.6.1affected
SUSESUSE Manager Proxy LTS 4.3? < 2.0.3-150000.3.6.1affected
SUSESUSE Manager Retail Branch Server LTS 4.3? < 2.0.3-150000.3.6.1affected
SUSESUSE Manager Retail Branch Server LTS 4.3? < 2.0.3-150000.3.6.1affected
SUSESUSE Manager Server LTS 4.3? < 2.0.3-150000.3.6.1affected
SUSESUSE Manager Server LTS 4.3? < 2.0.3-150000.3.6.1affected
SUSEopenSUSE Leap 16.0? < 2.0.7-160000.5.1affected
SUSEopenSUSE Leap 16.0? < 2.0.7-160000.5.1affected
SUSEopenSUSE Tumbleweed? < 2.0.7-3.1affected
SUSEopenSUSE Tumbleweed? < 2.0.7-3.1affected
SUSEopenSUSE Tumbleweed? < 2.0.7-3.1affected
SUSEopenSUSE Tumbleweed? < 2.0.7-3.1affected
libXfont2libXfont2? <= 2.0.8affected

Weaknesses

ADP Enrichment

CISA ADP Vulnrichment

  • SSVC:
  • Exploitation: none
    • Automatable: no
    • Technical Impact: total

References