CVE-2026-56003: CWE-122 Heap-based buffer overflow in X.Org libXfont2
CVE-2026-56003 is a heap-based buffer overflow vulnerability in the X.Org libXfont2 library affecting versions prior to 2.0.8. It occurs due to missing size checks in the property buffer when parsing PCF font files in the ComputeScaledProperties() function. Exploitation requires an authenticated X client and may lead to code execution within the X server. The vulnerability has a high severity with a CVSS score of 8.5. A patch is available to address this issue.
AI Analysis
Technical Summary
This vulnerability in libXfont2 arises from improper bounds checking on the property buffer during PCF font file parsing in the ComputeScaledProperties() function. An authenticated X client can exploit this heap-based buffer overflow to potentially execute arbitrary code within the X server process. The flaw affects all libXfont2 versions prior to 2.0.8. The issue is tracked as CWE-122 (heap-based buffer overflow) and has a CVSS v3.1 score of 8.5, indicating high impact on confidentiality, integrity, and availability. A patch has been released to fix the vulnerability.
Potential Impact
Successful exploitation can lead to arbitrary code execution within the X server, compromising system confidentiality, integrity, and availability. However, exploitation requires an authenticated X client, limiting the attack surface to users with access to the X server.
Mitigation Recommendations
A patch is available for libXfont2 version 2.0.8 and later. Users should upgrade to version 2.0.8 or newer to remediate this vulnerability. No additional mitigations are specified.
CVE-2026-56003: CWE-122 Heap-based buffer overflow in X.Org libXfont2
Description
CVE-2026-56003 is a heap-based buffer overflow vulnerability in the X.Org libXfont2 library affecting versions prior to 2.0.8. It occurs due to missing size checks in the property buffer when parsing PCF font files in the ComputeScaledProperties() function. Exploitation requires an authenticated X client and may lead to code execution within the X server. The vulnerability has a high severity with a CVSS score of 8.5. A patch is available to address this issue.
CVSS v3.1
Score 8.5high
Affected software
pkg:github/freedesktop/xorg/libxfontRun on your own infrastructure? Check whether these packages are installed with threat-finder — our free open-source scanner.
Weaknesses
AI-Powered Analysis
Machine-generated threat intelligence
Technical Analysis
This vulnerability in libXfont2 arises from improper bounds checking on the property buffer during PCF font file parsing in the ComputeScaledProperties() function. An authenticated X client can exploit this heap-based buffer overflow to potentially execute arbitrary code within the X server process. The flaw affects all libXfont2 versions prior to 2.0.8. The issue is tracked as CWE-122 (heap-based buffer overflow) and has a CVSS v3.1 score of 8.5, indicating high impact on confidentiality, integrity, and availability. A patch has been released to fix the vulnerability.
Potential Impact
Successful exploitation can lead to arbitrary code execution within the X server, compromising system confidentiality, integrity, and availability. However, exploitation requires an authenticated X client, limiting the attack surface to users with access to the X server.
Mitigation Recommendations
A patch is available for libXfont2 version 2.0.8 and later. Users should upgrade to version 2.0.8 or newer to remediate this vulnerability. No additional mitigations are specified.
Technical Details
- Data Version
- 5.2
- Assigner Short Name
- suse
- Date Reserved
- 2026-06-18T09:26:55.988Z
- Cvss Version
- 3.1
- State
- PUBLISHED
- Remediation Level
- null
Threat ID: 6a4e2371c9d9e3dbe3e2eb0a
Added to database: 07/08/2026, 10:16:17 UTC
Last enriched: 08/07/2026, 05:55:33 UTC
Last updated: 08/22/2026, 10:52:10 UTC
Views: 118
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