CVE Intelligence
Critical Memory corruption

CVE-2026-59679 — 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.

Published Sep 10, 2026 · Updated Oct 15, 2026 · Sources: NIST National Vulnerability Database, CVE Program (cve.org) e CISA ADP · CNA: suse

Who exploits it and how urgent it is

A 0–100 score combining confirmed exploitation, ransomware and APT use, public exploits, EPSS and severity.

No exploitation signal in the sources consulted so far.
How the score was calculated
  • EPSS 0.3% (30-day exploitation probability)+2
  • Technical severity (critical)+10

The score orders the patch queue; it does not replace your asset context (internet exposure, criticality, compensating controls).

Triage

Is it exploited, how likely is exploitation, what does it touch, and how severe do the sources call it.

Exploitation
Not confirmed
Not in CISA KEV — an absence of record, not proof it is unexploited.
EPSS FIRST
0.26%
ahead of 16% of scored CVEs · Oct 15, 2026
Affects
libXfont2
libXfont2 and 79 more
CVSS base
9.0
Critical · 2 source(s)

CISA SSVC assessment CISA

Three decision points CISA publishes for the CVEs it assesses (SSVC 2.0.3). A stakeholder decision, not a severity score.

Exploitation
None
none · proof-of-concept · active
Automatable
No
can an attacker script the kill-chain steps
Technical impact
Total
partial · total control of the vulnerable component

Remediation

Fixes and mitigations documented by the sources — linked to the original advisory.

No fix documented by the sources we poll. That does not mean none exists: check the vendor advisory.

First 24 hours

Ordered from the record’s own fields — exposure first, because you cannot patch what you have not found. A rule-generated starting point.

  1. Identify exposed assets running the affected vendor/product/version combinations (libXfont2 libXfont2, SUSE Container suse/kiosk/tigervnc-x11vnc:1.14-63.8, SUSE Container suse/kiosk/xorg:21.1-83.7…).
  2. The attack is network-based and needs no privileges: restrict exposure (ACLs, VPN, WAF) until patched.
  3. No fix documented in the sources: reduce exposure and monitor the vendor advisory.
  4. Search available logs for exploit probes matching the vulnerability class (memory corruption), errors and authentication anomalies.

Affected scope

Vendor, product and versions as the sources word them.

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

Attack characteristics

The CVSS vector, decoded. It describes the attack, not your exposure to it.

Attack vector
Network
Attack complexity
High
Privileges required
None
User interaction
None
Scope
Changed
Confidentiality
High
Integrity
High
Availability
High

Every base score collected

Sources score independently and may disagree; each row says who scored it and under which version.

ScoreVersionSeverityExpl.ImpactScored by
9.2 CVSS 4.0 Critical — — meissner@suse.de via NIST National Vulnerability Database
9.2 CVSS 4.0 Critical — — suse via CVE Program (cve.org) e CISA ADP
9.0 CVSS 3.1 Critical 2.2 6.0 meissner@suse.de via NIST National Vulnerability Database
9.0 CVSS 3.1 Critical — — suse via CVE Program (cve.org) e CISA ADP
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H (score shown at the top: meissner@suse.de)

Weakness MITRE

Weakness class according to MITRE’s CWE catalog.

CWE-787 · Out-of-bounds Write

Other CVEs with this weakness →

Detection

Read off the CVSS vector and the weakness class. Starting points, not tested rules.

  • Prioritize edge telemetry for the network-reachable component (proxy, WAF, IDS/IPS).
  • Correlate service crashes/restarts with inbound traffic; repeated crashes may indicate attempts.
web/proxy/WAF logsnetwork IDS/IPSendpoint telemetry (EDR)crash dumps

Timeline

What happened to this CVE, newest first.

  • 2026
  • Affected products added · suse/container suse/kiosk/tigervnc-x11vnc:1.14-63.8, suse/container suse/kiosk/xorg:21.1-83.7, suse/image sles15-sp6-sap
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • SSVC assessment updated
    Oct 15, 2026 · CVE Program (cve.org) e CISA ADP
  • Record published
    Oct 15, 2026
  • CVSS changed · 9.0
    Oct 15, 2026 · NIST National Vulnerability Database
  • Source status changed · → Awaiting Analysis
    Oct 15, 2026 · NIST National Vulnerability Database
  • Record created in this database
    Oct 15, 2026 · NIST National Vulnerability Database
  • CVE published
    Sep 10, 2026 · suse

Source activity

Repeated readings are counted rather than listed.

  • 1× Official description updated · Oct 15, 2026 – Oct 15, 2026

References

1 on the record

Elsewhere on this site

libXfont2
every CVE for this vendor
Memory corruption
same class
CWE-787
other pages naming this weakness

Related CVEs (same products)

  • CVE-2026-44950 fs_read_glyphs() heap buffer overflow via cumulative glyph data overflow in libXfont2 Sep 10, 2026
  • CVE-2026-59674 LPE from suricata user to root due to chown in %post in suricata packaging Jul 14, 2026
  • CVE-2026-41054 Missing exit out of permission check in haveged could lead to root exploit May 20, 2026
  • CVE-2026-41051 csync2 uses insecure temporary directories when compiled with C99 or later May 13, 2026
  • CVE-2025-62875 Local DoS in OpenSMTPD via UNIX domain socket smtpd.sock Nov 20, 2025
  • CVE-2025-53880 susemanager-tftpsync-recv allows arbitrary file creation and deletion due to path traversal Oct 30, 2025

Not in any source we poll

Listed rather than left blank: an empty field and an unmeasured one look identical on screen, and only one is a reason to look elsewhere.

  • No fixed version, patch or mitigation documented.
  • No confirmed IOCs, IP addresses, domains, file hashes, or malware artifacts supplied.
  • No organization-specific asset inventory, compensating-control status, or patch deployment evidence supplied.
  • No exploit packet captures, log samples, or incident case IDs supplied.

Answered from this record

Text assembled only from the fields above — no additional claims.

What should defenders know first?

CVE-2026-59679 is "fs_read_glyphs() heap OOB read/write via encoding array index mismatch in libXfont2", rated Critical. It affects libXfont2 (libXfont2); versions are in the scope table. It is not in CISA KEV, which does not rule out exploitation. CVSS 9.0 describes technical severity. EPSS 0.26% estimates the probability of exploitation in 30 days; neither replaces your asset context. First verify whether exposed or business-critical assets run the affected versions, apply vendor fixes or mitigations, and preserve logs for review.

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