fs_read_glyphs() heap buffer overflow via cumulative glyph data overflow in libXfont2
Summary
| CVE | CVE-2026-44950 |
|---|---|
| State | PUBLISHED |
| Assigner | suse |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-09-10 09:17:02 UTC |
| Updated | 2026-09-10 19:17:27 UTC |
| Description | 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. |
Risk And Classification
Primary CVSS: v4.0 9.5 CRITICAL from [email protected]
CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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: 0.004380000 probability, percentile 0.369290000 (date 2026-09-10)
Problem Types: CWE-122 | CWE-122 CWE-122 Heap-based Buffer Overflow
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 9.5 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/C... |
| 4.0 | CNA | CVSS | 9.5 | CRITICAL | CVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H |
| 3.1 | [email protected] | Secondary | 9 | CRITICAL | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H |
| 3.1 | CNA | CVSS | 9 | CRITICAL | CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H |
CVSS v4.0 Breakdown
Attack Vector
NetworkAttack Complexity
LowAttack Requirements
PresentPrivileges Required
NoneUser Interaction
NoneConfidentiality
HighIntegrity
HighAvailability
HighSub Conf.
HighSub Integrity
HighSub Availability
HighCVSS:4.0/AV:N/AC:L/AT:P/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/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
CVSS v3.1 Breakdown
Attack Vector
NetworkAttack Complexity
HighPrivileges Required
NoneUser Interaction
NoneScope
ChangedConfidentiality
HighIntegrity
HighAvailability
HighCVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:C/C:H/I:H/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | SUSE | Container Suse/kiosk/tigervnc-x11vnc1.14-63.8 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Container Suse/kiosk/xorg21.1-83.7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Azure-3P | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-BYOS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-BYOS-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-BYOS-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-BYOS-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Hardened | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Hardened-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Hardened-BYOS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Hardened-BYOS-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Hardened-BYOS-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Hardened-BYOS-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Hardened-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAP-Hardened-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAPCAL | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAPCAL-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAPCAL-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP6-SAPCAL-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-Azure-3P | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-BYOS-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-BYOS-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-BYOS-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-GCE-3P | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-Hardened-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-Hardened-BYOS-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-Hardened-BYOS-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-Hardened-BYOS-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAP-Hardened-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAPCAL-Azure | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAPCAL-EC2 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES15-SP7-SAPCAL-GCE | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES-SAP-Azure | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | Image SLES-SAP-Azure-3P | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | Image SLES-SAP-BYOS-Azure | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | Image SLES-SAP-BYOS-EC2 | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | Image SLES-SAP-BYOS-GCE | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | Image SLES-SAP-GCE | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | Image SLES-SAP-GCE-3P | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | Image SLES-SAPCAL-GCE | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | Image SLES12-SP5-Azure-SAP-BYOS | affected ? 2.0.3-3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES12-SP5-Azure-SAP-On-Demand | affected ? 2.0.3-3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES12-SP5-EC2-SAP-BYOS | affected ? 2.0.3-3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES12-SP5-EC2-SAP-On-Demand | affected ? 2.0.3-3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES12-SP5-GCE-SAP-BYOS | affected ? 2.0.3-3.6.1 custom | Not specified |
| CNA | SUSE | Image SLES12-SP5-GCE-SAP-On-Demand | affected ? 2.0.3-3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Liberty Linux 10 | affected ? 2.0.6-5.el10_2.3 custom | Not specified |
| CNA | SUSE | SUSE Liberty Linux 10 | affected ? 2.0.6-5.el10_2.3 custom | Not specified |
| CNA | SUSE | SUSE Liberty Linux 8 | affected ? 2.0.3-2.el8_10.3 custom | Not specified |
| CNA | SUSE | SUSE Liberty Linux 8 | affected ? 2.0.3-2.el8_10.3 custom | Not specified |
| CNA | SUSE | SUSE Liberty Linux 9 | affected ? 2.0.3-12.el9_8.3 custom | Not specified |
| CNA | SUSE | SUSE Liberty Linux 9 | affected ? 2.0.3-12.el9_8.3 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Desktop 15 SP7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Desktop 15 SP7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Module For Basesystem 15 SP7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Module For Basesystem 15 SP7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 15 SP7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 15 SP7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 15 SP7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 15 SP7 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise High Performance Computing 15 SP4-ESPOS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise High Performance Computing 15 SP4-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise High Performance Computing 15 SP5-ESPOS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise High Performance Computing 15 SP5-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 12 SP5-LTSS | affected ? 2.0.3-3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 15 SP4-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 15 SP4-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 15 SP5-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 15 SP5-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 15 SP6-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 15 SP6-LTSS | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 16.0 | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server 16.0 | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 16.0 | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 16.0 | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server LTSS Extended Security 12 SP5 | affected ? 2.0.3-3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 15 SP4 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 15 SP4 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 15 SP5 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 15 SP5 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 15 SP6 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Linux Enterprise Server For SAP Applications 15 SP6 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Manager Proxy LTS 4.3 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Manager Proxy LTS 4.3 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Manager Retail Branch Server LTS 4.3 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Manager Retail Branch Server LTS 4.3 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Manager Server LTS 4.3 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | SUSE Manager Server LTS 4.3 | affected ? 2.0.3-150000.3.6.1 custom | Not specified |
| CNA | SUSE | OpenSUSE Leap 16.0 | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | OpenSUSE Leap 16.0 | affected ? 2.0.7-160000.5.1 custom | Not specified |
| CNA | SUSE | OpenSUSE Tumbleweed | affected ? 2.0.7-3.1 custom | Not specified |
| CNA | SUSE | OpenSUSE Tumbleweed | affected ? 2.0.7-3.1 custom | Not specified |
| CNA | SUSE | OpenSUSE Tumbleweed | affected ? 2.0.7-3.1 custom | Not specified |
| CNA | SUSE | OpenSUSE Tumbleweed | affected ? 2.0.7-3.1 custom | Not specified |
| CNA | LibXfont | LibXfont | affected ? 2.0.8 custom | Not specified |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| bugzilla.suse.com/show_bug.cgi | [email protected] | bugzilla.suse.com | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Vendor Comments And Credit
Discovery Credit
CNA: zx (Jace) (en)
There are currently no legacy QID mappings associated with this CVE.