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9.4

CVE-2026-59679: libXfont2 font client may read/write memory unexpectedly

CVE-2026-59679 · published 11 days ago
Summary

The libXfont2 library used in Debian and several SUSE Linux images can be fooled by a malicious font server into reading and writing memory outside its allocated area. This occurs because the software does not verify that two size values sent by the server match, allowing an attacker to trigger out‑of‑bounds access. Update the libXfont2 package to the latest version or apply the vendor’s security patch to fix the issue.

What to do
  • Update debian libxfont to version 1:2.0.9-1.
  • Update suse container suse/kiosk/tigervnc-x11vnc:1.14-63.8 to version 2.0.3-150000.3.6.1 or later.
  • Update suse container suse/kiosk/xorg:21.1-83.7 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-azure-3p to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-byos to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-byos-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-byos-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-byos-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-hardened to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-hardened-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-hardened-byos to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-hardened-byos-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-hardened-byos-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-hardened-byos-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-hardened-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sap-hardened-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sapcal to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sapcal-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sapcal-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp6-sapcal-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-azure-3p to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-byos-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-byos-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-byos-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-gce-3p to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-hardened-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-hardened-byos-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-hardened-byos-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-hardened-byos-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sap-hardened-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sapcal-azure to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sapcal-ec2 to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles15-sp7-sapcal-gce to version 2.0.3-150000.3.6.1 or later.
  • Update suse image sles-sap-azure to version 2.0.7-160000.5.1 or later.
  • Update suse image sles-sap-azure-3p to version 2.0.7-160000.5.1 or later.
  • Update suse image sles-sap-byos-azure to version 2.0.7-160000.5.1 or later.
  • Update suse image sles-sap-byos-ec2 to version 2.0.7-160000.5.1 or later.
  • Update suse image sles-sap-byos-gce to version 2.0.7-160000.5.1 or later.
  • Update suse image sles-sap-gce to version 2.0.7-160000.5.1 or later.
  • Update suse image sles-sap-gce-3p to version 2.0.7-160000.5.1 or later.
  • Update suse image sles-sapcal-gce to version 2.0.7-160000.5.1 or later.
  • Update suse image sles12-sp5-azure-sap-byos to version 2.0.3-3.6.1 or later.
  • Update suse image sles12-sp5-azure-sap-on-demand to version 2.0.3-3.6.1 or later.
  • Update suse image sles12-sp5-ec2-sap-byos to version 2.0.3-3.6.1 or later.
  • Update suse image sles12-sp5-ec2-sap-on-demand to version 2.0.3-3.6.1 or later.
  • Update suse image sles12-sp5-gce-sap-byos to version 2.0.3-3.6.1 or later.
  • Update suse image sles12-sp5-gce-sap-on-demand to version 2.0.3-3.6.1 or later.
  • Update suse suse liberty linux 10 to version 2.0.6-5.el10_2.3 or later.
  • Update suse suse liberty linux 8 to version 2.0.3-2.el8_10.3 or later.
  • Update suse suse liberty linux 9 to version 2.0.3-12.el9_8.3 or later.
  • Update suse suse linux enterprise desktop 15 sp7 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise module for basesystem 15 sp7 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise server 15 sp7 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise server for sap applications 15 sp7 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise high performance computing 15 sp4-espos to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise high performance computing 15 sp4-ltss to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise high performance computing 15 sp5-espos to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise high performance computing 15 sp5-ltss to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise server 12 sp5-ltss to version 2.0.3-3.6.1 or later.
  • Update suse suse linux enterprise server 15 sp4-ltss to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise server 15 sp5-ltss to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise server 15 sp6-ltss to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise server 16.0 to version 2.0.7-160000.5.1 or later.
  • Update suse suse linux enterprise server for sap applications 16.0 to version 2.0.7-160000.5.1 or later.
  • Update suse suse linux enterprise server ltss extended security 12 sp5 to version 2.0.3-3.6.1 or later.
  • Update suse suse linux enterprise server for sap applications 15 sp4 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise server for sap applications 15 sp5 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse linux enterprise server for sap applications 15 sp6 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse manager proxy lts 4.3 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse manager retail branch server lts 4.3 to version 2.0.3-150000.3.6.1 or later.
  • Update suse suse manager server lts 4.3 to version 2.0.3-150000.3.6.1 or later.
  • Update suse opensuse leap 16.0 to version 2.0.7-160000.5.1 or later.
  • Update suse opensuse tumbleweed to version 2.0.7-3.1 or later.
Affected software
Ecosystem VendorProductAffected versions
Debian:11 debian libxfont All versions
Debian:12 debian libxfont All versions
Debian:13 debian libxfont All versions
Debian:14 debian libxfont < 1:2.0.9-1
Fix: upgrade to 1:2.0.9-1
suse container suse/kiosk/tigervnc-x11vnc:1.14-63.8 < 2.0.3-150000.3.6.1
suse container suse/kiosk/xorg:21.1-83.7 < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-azure < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-azure-3p < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-byos < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-byos-azure < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-byos-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-byos-gce < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-gce < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-hardened < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-hardened-azure < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-hardened-byos < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-hardened-byos-azure < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-hardened-byos-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-hardened-byos-gce < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-hardened-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp6-sap-hardened-gce < 2.0.3-150000.3.6.1
suse image sles15-sp6-sapcal < 2.0.3-150000.3.6.1
suse image sles15-sp6-sapcal-azure < 2.0.3-150000.3.6.1
suse image sles15-sp6-sapcal-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp6-sapcal-gce < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-azure < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-azure-3p < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-byos-azure < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-byos-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-byos-gce < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-gce < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-gce-3p < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-hardened-azure < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-hardened-byos-azure < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-hardened-byos-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-hardened-byos-gce < 2.0.3-150000.3.6.1
suse image sles15-sp7-sap-hardened-gce < 2.0.3-150000.3.6.1
suse image sles15-sp7-sapcal-azure < 2.0.3-150000.3.6.1
suse image sles15-sp7-sapcal-ec2 < 2.0.3-150000.3.6.1
suse image sles15-sp7-sapcal-gce < 2.0.3-150000.3.6.1
suse image sles-sap-azure < 2.0.7-160000.5.1
suse image sles-sap-azure-3p < 2.0.7-160000.5.1
suse image sles-sap-byos-azure < 2.0.7-160000.5.1
suse image sles-sap-byos-ec2 < 2.0.7-160000.5.1
suse image sles-sap-byos-gce < 2.0.7-160000.5.1
suse image sles-sap-gce < 2.0.7-160000.5.1
suse image sles-sap-gce-3p < 2.0.7-160000.5.1
Showing 50 of 86. Show the rest
Ecosystem VendorProductAffected versions
suse image sles-sapcal-gce < 2.0.7-160000.5.1
suse image sles12-sp5-azure-sap-byos < 2.0.3-3.6.1
suse image sles12-sp5-azure-sap-on-demand < 2.0.3-3.6.1
suse image sles12-sp5-ec2-sap-byos < 2.0.3-3.6.1
suse image sles12-sp5-ec2-sap-on-demand < 2.0.3-3.6.1
suse image sles12-sp5-gce-sap-byos < 2.0.3-3.6.1
suse image sles12-sp5-gce-sap-on-demand < 2.0.3-3.6.1
suse suse liberty linux 10 < 2.0.6-5.el10_2.3
suse suse liberty linux 8 < 2.0.3-2.el8_10.3
suse suse liberty linux 9 < 2.0.3-12.el9_8.3
suse suse linux enterprise desktop 15 sp7 < 2.0.3-150000.3.6.1
suse suse linux enterprise module for basesystem 15 sp7 < 2.0.3-150000.3.6.1
suse suse linux enterprise server 15 sp7 < 2.0.3-150000.3.6.1
suse suse linux enterprise server for sap applications 15 sp7 < 2.0.3-150000.3.6.1
suse suse linux enterprise high performance computing 15 sp4-espos < 2.0.3-150000.3.6.1
suse suse linux enterprise high performance computing 15 sp4-ltss < 2.0.3-150000.3.6.1
suse suse linux enterprise high performance computing 15 sp5-espos < 2.0.3-150000.3.6.1
suse suse linux enterprise high performance computing 15 sp5-ltss < 2.0.3-150000.3.6.1
suse suse linux enterprise server 12 sp5-ltss < 2.0.3-3.6.1
suse suse linux enterprise server 15 sp4-ltss < 2.0.3-150000.3.6.1
suse suse linux enterprise server 15 sp5-ltss < 2.0.3-150000.3.6.1
suse suse linux enterprise server 15 sp6-ltss < 2.0.3-150000.3.6.1
suse suse linux enterprise server 16.0 < 2.0.7-160000.5.1
suse suse linux enterprise server for sap applications 16.0 < 2.0.7-160000.5.1
suse suse linux enterprise server ltss extended security 12 sp5 < 2.0.3-3.6.1
suse suse linux enterprise server for sap applications 15 sp4 < 2.0.3-150000.3.6.1
suse suse linux enterprise server for sap applications 15 sp5 < 2.0.3-150000.3.6.1
suse suse linux enterprise server for sap applications 15 sp6 < 2.0.3-150000.3.6.1
suse suse manager proxy lts 4.3 < 2.0.3-150000.3.6.1
suse suse manager retail branch server lts 4.3 < 2.0.3-150000.3.6.1
suse suse manager server lts 4.3 < 2.0.3-150000.3.6.1
suse opensuse leap 16.0 < 2.0.7-160000.5.1
suse opensuse tumbleweed < 2.0.7-3.1
libxfont2 libxfont2 <= 2.0.8
Ubuntu:Pro:14.04:LTS canonical libxfont All versions
Ubuntu:16.04:LTS canonical libxfont2 All versions
Original advisory text
fs_read_glyphs() heap OOB read/write via encoding array index mismatch in libXfont2
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.
Severity
9.4 Critical
Exploitation
EPSS <1%
Type
CWE-787Out-of-bounds Write
Timeline
Published10 Sep 2026
Updated19 Sep 2026
First seen10 Aug 2026
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