CVE-2026-59679fs_read_glyphs() heap OOB read/write via encoding array index mismatch in libXfont2

9.2CriticalCVSS base score
0.26%Exploitation in 30 daysEPSS · top 83% of all CVEs
NoKnown exploitednot in CISA's KEV catalog
NonePublic exploitsnone known yet

Description

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.

Timeline

2026
6 Jul 2026
6 Jul 2026
ID reserved
By suse
10 Sept 20262 months later
10 Sept 2026· 2 months later
Published

Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.

Scores

CVSS scores of CVE-2026-59679, by who scored it
Scored by	CVSS	Score	Vector
suseCNA (assigner)	4.0	Critical9.2	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N
suseCNA (assigner)	3.1	Critical9.0	CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
NVDNVD · Awaiting Analysis	4.0	Critical9.2	CVSS:4.0/AV:N/AC:H/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X

EPSS (exploitation in 30 days): 0.26% · top 83% of all CVEs (15 Nov 2026)
CISA SSVC: Exploitation: none · Automatable: no · Technical impact: total

The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.2.

Affected products

SUSE · Container suse/kiosk/tigervnc-x11vnc:1.14-63.8
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Container suse/kiosk/xorg:21.1-83.7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Azure-3P
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-BYOS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-BYOS-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-BYOS-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-BYOS-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Hardened
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Hardened-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Hardened-BYOS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Hardened-BYOS-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Hardened-BYOS-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Hardened-BYOS-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Hardened-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAP-Hardened-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAPCAL
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAPCAL-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAPCAL-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP6-SAPCAL-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-Azure-3P
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-BYOS-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-BYOS-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-BYOS-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-GCE-3P
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-Hardened-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-Hardened-BYOS-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-Hardened-BYOS-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-Hardened-BYOS-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAP-Hardened-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAPCAL-Azure
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAPCAL-EC2
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES15-SP7-SAPCAL-GCE
- affected ? – < 2.0.3-150000.3.6.1
SUSE · Image SLES-SAP-Azure
- affected ? – < 2.0.7-160000.5.1
SUSE · Image SLES-SAP-Azure-3P
- affected ? – < 2.0.7-160000.5.1
SUSE · Image SLES-SAP-BYOS-Azure
- affected ? – < 2.0.7-160000.5.1
SUSE · Image SLES-SAP-BYOS-EC2
- affected ? – < 2.0.7-160000.5.1
SUSE · Image SLES-SAP-BYOS-GCE
- affected ? – < 2.0.7-160000.5.1
SUSE · Image SLES-SAP-GCE
- affected ? – < 2.0.7-160000.5.1
SUSE · Image SLES-SAP-GCE-3P
- affected ? – < 2.0.7-160000.5.1
SUSE · Image SLES-SAPCAL-GCE
- affected ? – < 2.0.7-160000.5.1
SUSE · Image SLES12-SP5-Azure-SAP-BYOS
- affected ? – < 2.0.3-3.6.1
SUSE · Image SLES12-SP5-Azure-SAP-On-Demand
- affected ? – < 2.0.3-3.6.1
SUSE · Image SLES12-SP5-EC2-SAP-BYOS
- affected ? – < 2.0.3-3.6.1
SUSE · Image SLES12-SP5-EC2-SAP-On-Demand
- affected ? – < 2.0.3-3.6.1
SUSE · Image SLES12-SP5-GCE-SAP-BYOS
- affected ? – < 2.0.3-3.6.1
SUSE · Image SLES12-SP5-GCE-SAP-On-Demand
- affected ? – < 2.0.3-3.6.1
SUSE · SUSE Liberty Linux 10
- affected ? – < 2.0.6-5.el10_2.3
SUSE · SUSE Liberty Linux 10
- affected ? – < 2.0.6-5.el10_2.3
SUSE · SUSE Liberty Linux 8
- affected ? – < 2.0.3-2.el8_10.3
SUSE · SUSE Liberty Linux 8
- affected ? – < 2.0.3-2.el8_10.3
SUSE · SUSE Liberty Linux 9
- affected ? – < 2.0.3-12.el9_8.3
SUSE · SUSE Liberty Linux 9
- affected ? – < 2.0.3-12.el9_8.3
SUSE · SUSE Linux Enterprise Desktop 15 SP7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Desktop 15 SP7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Module for Basesystem 15 SP7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Module for Basesystem 15 SP7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 15 SP7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 15 SP7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server for SAP Applications 15 SP7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server for SAP Applications 15 SP7
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 12 SP5-LTSS
- affected ? – < 2.0.3-3.6.1
SUSE · SUSE Linux Enterprise Server 15 SP4-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 15 SP4-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 15 SP5-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 15 SP5-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 15 SP6-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 15 SP6-LTSS
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server 16.0
- affected ? – < 2.0.7-160000.5.1
SUSE · SUSE Linux Enterprise Server 16.0
- affected ? – < 2.0.7-160000.5.1
SUSE · SUSE Linux Enterprise Server for SAP applications 16.0
- affected ? – < 2.0.7-160000.5.1
SUSE · SUSE Linux Enterprise Server for SAP applications 16.0
- affected ? – < 2.0.7-160000.5.1
SUSE · SUSE Linux Enterprise Server LTSS Extended Security 12 SP5
- affected ? – < 2.0.3-3.6.1
SUSE · SUSE Linux Enterprise Server for SAP Applications 15 SP4
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server for SAP Applications 15 SP4
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server for SAP Applications 15 SP5
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server for SAP Applications 15 SP5
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server for SAP Applications 15 SP6
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Linux Enterprise Server for SAP Applications 15 SP6
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Manager Proxy LTS 4.3
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Manager Proxy LTS 4.3
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Manager Retail Branch Server LTS 4.3
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Manager Retail Branch Server LTS 4.3
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Manager Server LTS 4.3
- affected ? – < 2.0.3-150000.3.6.1
SUSE · SUSE Manager Server LTS 4.3
- affected ? – < 2.0.3-150000.3.6.1
SUSE · openSUSE Leap 16.0
- affected ? – < 2.0.7-160000.5.1
SUSE · openSUSE Leap 16.0
- affected ? – < 2.0.7-160000.5.1
SUSE · openSUSE Tumbleweed
- affected ? – < 2.0.7-3.1
SUSE · openSUSE Tumbleweed
- affected ? – < 2.0.7-3.1
SUSE · openSUSE Tumbleweed
- affected ? – < 2.0.7-3.1
SUSE · openSUSE Tumbleweed
- affected ? – < 2.0.7-3.1
libXfont2 · libXfont2
- affected ? – ≤ 2.0.8

References1

https://bugzilla.suse.com/show_bug.cgi?id=CVE-2026-59679 (opens in a new tab)

Sources

The same CVE in the primary databases and aggregators, to check against.

Badge for a README or a ticket

[![CVE-2026-59679](https://cveledger.app/badge/CVE-2026-59679.svg)](https://cveledger.app/cve/CVE-2026-59679)

Record last updated 10 Sept 2026, 12:45 UTC.