by Kastro CVE-2026-59679
SUSE Container suse/kiosk/tigervnc-x11vnc:1.14-63.8 — fs_read_glyphs() heap OOB read/write via encoding array index mismatch in libXfont2
Description · from the CVE record
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
ProductAffectedFixed inSource
Container suse/kiosk/tigervnc-x11vnc:1.14-63.8? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Container suse/kiosk/xorg:21.1-83.7? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-Azure? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-Azure-3P? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-BYOS? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-BYOS-Azure? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-BYOS-EC2? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-BYOS-GCE? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-EC2? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-GCE? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Image SLES15-SP6-SAP-Hardened? – < 2.0.3-150000.3.6.12.0.3-150000.3.6.1CNA
Scores by source
suse (CNA)9.2CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
suse (CNA)9.0CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
CISA ADPSSVCExploitation: none · Automatable: no · Technical impact: total