CVE-2026-44950
Fixed in a distro release EPSS <1%CVSS 9.0
fs_read_glyphs() in the libXfont2 font-server client (src/fc/fserve.c) copies each glyph's bitmap into a single buffer. Existing checks validates only that the source slice (position, length) lies within the source bitmap buffer. It does not check whether the running destination cursor has exceeded the allocation. A malicious font server can send overlapping source offsets -- for example 1000 glyphs each referencing {position:0, length:64} with nbytes=64. Each individual source range passes the existing validation, but the cumulative writes total 64000 bytes into a 64-byte destination buffer. This is a heap buffer overflow with attacker-controlled content.
Products: Container suse/kiosk/tigervnc-x11vnc:1.14-63.8, Container suse/kiosk/xorg:21.1-83.7, SUSE Image SLES15-SP6-SAP, SUSE Image SLES15-SP6-SAP-Azure, SUSE Image SLES15-SP6-SAP-Azure-3P, SUSE Image SLES15-SP6-SAP-BYOS, SUSE Image SLES15-SP6-SAP-BYOS-Azure, SUSE Image SLES15-SP6-SAP-BYOS-EC2, SUSE Image SLES15-SP6-SAP-BYOS-GCE, SUSE Image SLES15-SP6-SAP-EC2, SUSE Image SLES15-SP6-SAP-GCE, SUSE Image SLES15-SP6-SAP-Hardened, SUSE Image SLES15-SP6-SAP-Hardened-Azure, SUSE Image SLES15-SP6-SAP-Hardened-BYOS, SUSE Image SLES15-SP6-SAP-Hardened-BYOS-Azure, SUSE Image SLES15-SP6-SAP-Hardened-BYOS-EC2, SUSE Image SLES15-SP6-SAP-Hardened-BYOS-GCE, SUSE Image SLES15-SP6-SAP-Hardened-EC2, SUSE Image SLES15-SP6-SAP-Hardened-GCE, SUSE Image SLES15-SP6-SAPCAL, SUSE Image SLES15-SP6-SAPCAL-Azure, SUSE Image SLES15-SP6-SAPCAL-EC2, SUSE Image SLES15-SP6-SAPCAL-GCE, SUSE Image SLES15-SP7-SAP-Azure, SUSE Image SLES15-SP7-SAP-Azure-3P, SUSE Image SLES15-SP7-SAP-BYOS-Azure, SUSE Image SLES15-SP7-SAP-BYOS-EC2, SUSE Image SLES15-SP7-SAP-BYOS-GCE, SUSE Image SLES15-SP7-SAP-EC2, SUSE Image SLES15-SP7-SAP-GCE, SUSE Image SLES15-SP7-SAP-GCE-3P, SUSE Image SLES15-SP7-SAP-Hardened-Azure, SUSE Image SLES15-SP7-SAP-Hardened-BYOS-Azure, SUSE Image SLES15-SP7-SAP-Hardened-BYOS-EC2, SUSE Image SLES15-SP7-SAP-Hardened-BYOS-GCE, SUSE Image SLES15-SP7-SAP-Hardened-GCE, SUSE Image SLES15-SP7-SAPCAL-Azure, SUSE Image SLES15-SP7-SAPCAL-EC2, SUSE Image SLES15-SP7-SAPCAL-GCE, SUSE Image SLES-SAP-Azure, SUSE Image SLES-SAP-Azure-3P, SUSE Image SLES-SAP-BYOS-Azure, SUSE Image SLES-SAP-BYOS-EC2, SUSE Image SLES-SAP-BYOS-GCE, SUSE Image SLES-SAP-GCE, SUSE Image SLES-SAP-GCE-3P, SUSE Image SLES-SAPCAL-GCE, SUSE Image SLES12-SP5-Azure-SAP-BYOS, SUSE Image SLES12-SP5-Azure-SAP-On-Demand, SUSE Image SLES12-SP5-EC2-SAP-BYOS, SUSE Image SLES12-SP5-EC2-SAP-On-Demand, SUSE Image SLES12-SP5-GCE-SAP-BYOS, SUSE Image SLES12-SP5-GCE-SAP-On-Demand, SUSE Liberty Linux 10, SUSE Liberty Linux 8, SUSE Liberty Linux 9, SUSE Linux Enterprise Desktop 15 SP7, SUSE Linux Enterprise Module for Basesystem 15 SP7, SUSE Linux Enterprise Server 15 SP7, SUSE Linux Enterprise Server for SAP Applications 15 SP7, SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS, SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS, SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS, SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS, SUSE Linux Enterprise Server 12 SP5-LTSS, SUSE Linux Enterprise Server 15 SP4-LTSS, SUSE Linux Enterprise Server 15 SP5-LTSS, SUSE Linux Enterprise Server 15 SP6-LTSS, SUSE Linux Enterprise Server 16.0, SUSE Linux Enterprise Server for SAP applications 16.0, SUSE Linux Enterprise Server LTSS Extended Security 12 SP5, SUSE Linux Enterprise Server for SAP Applications 15 SP4, SUSE Linux Enterprise Server for SAP Applications 15 SP5, SUSE Linux Enterprise Server for SAP Applications 15 SP6, SUSE Manager Proxy LTS 4.3, SUSE Manager Retail Branch Server LTS 4.3, SUSE Manager Server LTS 4.3, openSUSE Leap 16.0, openSUSE Tumbleweed, libXfont
Distro releases
| Release | Package | Fixed in |
|---|---|---|
| AlmaLinux 10 | libXfont2 | 2.0.6-5.el10_2.3 |
| AlmaLinux 10 | libXfont2-devel | 2.0.6-5.el10_2.3 |
| AlmaLinux 8 | libXfont2 | 2.0.3-2.el8_10.3 |
| AlmaLinux 8 | libXfont2-devel | 2.0.3-2.el8_10.3 |
| AlmaLinux 9 | libXfont2 | 2.0.3-12.el9_8.3 |
| AlmaLinux 9 | libXfont2-devel | 2.0.3-12.el9_8.3 |
| Amazon Linux 2 | libXfont | 1.5.4-1.amzn2.0.2 |
| Amazon Linux 2 | libXfont-devel | 1.5.4-1.amzn2.0.2 |
| Amazon Linux 2 | libXfont2 | 2.0.3-1.amzn2.0.2 |
| Amazon Linux 2 | libXfont2-devel | 2.0.3-1.amzn2.0.2 |
| Amazon Linux 2023 | libXfont2 | 2.0.7-1.amzn2023.0.3 |
| Amazon Linux 2023 | libXfont2-devel | 2.0.7-1.amzn2023.0.3 |
| Debian 12 | libxfont | no fix |
| Debian 13 | libxfont | no fix |
| Debian 14 | libxfont | 1:2.0.9-1 |
| Red Hat Enterprise Linux 10.2 | libXfont2 | 0:2.0.6-5.el10_2.3 |
| Red Hat Enterprise Linux 10.2 | libXfont2-debuginfo | 0:2.0.6-5.el10_2.3 |
| Red Hat Enterprise Linux 10.2 | libXfont2-debugsource | 0:2.0.6-5.el10_2.3 |
| Red Hat Enterprise Linux 10.2 | libXfont2-devel | 0:2.0.6-5.el10_2.3 |
| Red Hat Enterprise Linux 8 | libXfont2 | 0:2.0.3-2.el8_10.3 |
| Red Hat Enterprise Linux 8 | libXfont2-debuginfo | 0:2.0.3-2.el8_10.3 |
| Red Hat Enterprise Linux 8 | libXfont2-debugsource | 0:2.0.3-2.el8_10.3 |
| Red Hat Enterprise Linux 8 | libXfont2-devel | 0:2.0.3-2.el8_10.3 |
| Red Hat Enterprise Linux 9 | libXfont2 | 0:2.0.3-12.el9_8.3 |
| Red Hat Enterprise Linux 9 | libXfont2-debuginfo | 0:2.0.3-12.el9_8.3 |
| Red Hat Enterprise Linux 9 | libXfont2-debugsource | 0:2.0.3-12.el9_8.3 |
| Red Hat Enterprise Linux 9 | libXfont2-devel | 0:2.0.3-12.el9_8.3 |
| Red Hat Enterprise Linux eus 10.0 | libXfont2 | 0:2.0.6-5.el10_0.2 |
| Red Hat Enterprise Linux eus 10.0 | libXfont2-debuginfo | 0:2.0.6-5.el10_0.2 |
| Red Hat Enterprise Linux eus 10.0 | libXfont2-debugsource | 0:2.0.6-5.el10_0.2 |
| Red Hat Enterprise Linux eus 10.0 | libXfont2-devel | 0:2.0.6-5.el10_0.2 |
| Red Hat rhel aus 8.4 | libXfont2 | 0:2.0.3-2.el8_4.2 |
| Red Hat rhel aus 8.4 | libXfont2-debuginfo | 0:2.0.3-2.el8_4.2 |
| Red Hat rhel aus 8.4 | libXfont2-debugsource | 0:2.0.3-2.el8_4.2 |
| Red Hat rhel aus 8.6 | libXfont2 | 0:2.0.3-2.el8_6.2 |
| Red Hat rhel aus 8.6 | libXfont2-debuginfo | 0:2.0.3-2.el8_6.2 |
| Red Hat rhel aus 8.6 | libXfont2-debugsource | 0:2.0.3-2.el8_6.2 |
| Red Hat rhel e4s 8.8 | libXfont2 | 0:2.0.3-2.el8_8.2 |
| Red Hat rhel e4s 8.8 | libXfont2-debuginfo | 0:2.0.3-2.el8_8.2 |
| Red Hat rhel e4s 8.8 | libXfont2-debugsource | 0:2.0.3-2.el8_8.2 |
| Red Hat rhel e4s 9.2 | libXfont2 | 0:2.0.3-12.el9_2.3 |
| Red Hat rhel e4s 9.2 | libXfont2-debuginfo | 0:2.0.3-12.el9_2.3 |
| Red Hat rhel e4s 9.2 | libXfont2-debugsource | 0:2.0.3-12.el9_2.3 |
| Red Hat rhel e4s 9.4 | libXfont2 | 0:2.0.3-12.el9_4.3 |
| Red Hat rhel e4s 9.4 | libXfont2-debuginfo | 0:2.0.3-12.el9_4.3 |
| Red Hat rhel e4s 9.4 | libXfont2-debugsource | 0:2.0.3-12.el9_4.3 |
| Red Hat rhel els 7 | libXfont2 | 0:2.0.3-3.el7_9 |
| Red Hat rhel els 7 | libXfont2-debuginfo | 0:2.0.3-3.el7_9 |
| Red Hat rhel els 7 | libXfont2-devel | 0:2.0.3-3.el7_9 |
| Red Hat rhel eus 9.6 | libXfont2 | 0:2.0.3-12.el9_6.3 |
| Red Hat rhel eus 9.6 | libXfont2-debuginfo | 0:2.0.3-12.el9_6.3 |
| Red Hat rhel eus 9.6 | libXfont2-debugsource | 0:2.0.3-12.el9_6.3 |
| Red Hat rhel eus 9.6 | libXfont2-devel | 0:2.0.3-12.el9_6.3 |
| Red Hat rhel eus long life 8.4 | libXfont2 | 0:2.0.3-2.el8_4.2 |
| Red Hat rhel eus long life 8.4 | libXfont2-debuginfo | 0:2.0.3-2.el8_4.2 |
| Red Hat rhel eus long life 8.4 | libXfont2-debugsource | 0:2.0.3-2.el8_4.2 |
| Red Hat rhel eus long life 8.6 | libXfont2 | 0:2.0.3-2.el8_6.2 |
| Red Hat rhel eus long life 8.6 | libXfont2-debuginfo | 0:2.0.3-2.el8_6.2 |
| Red Hat rhel eus long life 8.6 | libXfont2-debugsource | 0:2.0.3-2.el8_6.2 |
| Red Hat rhel tus 8.8 | libXfont2 | 0:2.0.3-2.el8_8.2 |
| Red Hat rhel tus 8.8 | libXfont2-debuginfo | 0:2.0.3-2.el8_8.2 |
| Red Hat rhel tus 8.8 | libXfont2-debugsource | 0:2.0.3-2.el8_8.2 |
| Rocky Linux 10 | libXfont2 | 0:2.0.6-5.el10_2.3 |
| Rocky Linux 8 | libXfont2 | 0:2.0.3-2.el8_10.3 |
| Rocky Linux 9 | libXfont2 | 0:2.0.3-12.el9_8.3 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise Module for Basesystem 15 SP7 | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise Server 12 SP5-LTSS | libXfont2 | 2.0.3-3.6.1 |
| SUSE Linux Enterprise Server 15 SP4-LTSS | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise Server 15 SP5-LTSS | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise Server 15 SP6-LTSS | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise Server 16.0 | libXfont2 | 2.0.7-160000.5.1 |
| SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | libXfont2 | 2.0.3-3.6.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP4 | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP5 | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise Server for SAP Applications 15 SP6 | libXfont2 | 2.0.3-150000.3.6.1 |
| SUSE Linux Enterprise Server for SAP applications 16.0 | libXfont2 | 2.0.7-160000.5.1 |
| Ubuntu 16.04 LTS | libxfont2 | no fix |
| openSUSE Leap 16.0 | libXfont2 | 2.0.7-160000.5.1 |
| openSUSE Tumbleweed | libXfont2 | 2.0.7-3.1 |