SB20260721110 - Ubuntu update for libxfont

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Main Vulnerability Database SB20260721110

SB20260721110 - Ubuntu update for libxfont

Published: July 21, 2026

Security Bulletin ID SB20260721110
CSH Severity
Low
Patch available
YES
Number of vulnerabilities 4
Exploitation vector Local access
Highest impact Code execution

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 4 vulnerabilities.


1) Integer overflow (CVE-ID: CVE-2026-56001)

CWE-ID: CWE-190 - Integer overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to escalate privileges on the target system.

The vulnerability exists due to integer overflow within the BitmapScaleBitmaps function. A local user can pass specially crafted data to the application, trigger integer overflow and gain elevated privileges on the target system.


2) Heap-based buffer overflow (CVE-ID: CVE-2026-56002)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to escalate privileges on the target system.

The vulnerability exists due to a boundary error within the pcfReadFont function. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and gain elevated privileges on the target system.


3) Heap-based buffer overflow (CVE-ID: CVE-2026-56003)

CWE-ID: CWE-122 - Heap-based Buffer Overflow

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local user to escalate privileges on the target system.

The vulnerability exists due to a boundary error within the ComputeScaledProperties function. A local user can pass specially crafted data to the application, trigger a heap-based buffer overflow and gain elevated privileges on the target system.


4) Privilege escalation (CVE-ID: CVE-2017-16611)

CWE-ID: CWE-264 - Permissions, Privileges, and Access Controls

CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N/E:U/U:Clear


The vulnerability allows a local attacker to gain elevated privileges on the target system.

The weakness exists due to improper privileges control. A local attacker can open (but not read) files on the system as root, triggering tape rewinds, watchdogs, or similar mechanisms that can be triggered by opening files.

Remediation

Install update from vendor's website.

References