# CVE-2026-56003: libXfont2 computeProps Property Buffer Heap Buffer Overflow CVE-2026-56003 is fixed in 6 products on 1 platform, first by libxfont2 1:2.0.6-2ubuntu0.2, released July 8, 2026. It is not reported as exploited. Patch Radar priority: High. - Web page: https://patchblox.com/security/cve/CVE-2026-56003 - Priority: High - CVSS: 8.8 (Important) - EPSS: 0.0040 - CISA KEV: not listed - Exploited (vendor report): no - Publicly disclosed: no - Published: Jul 8, 2026 - Weakness: Heap-based Buffer Overflow - Vendor advisory: https://msrc.microsoft.com/update-guide/vulnerability/CVE-2026-56003 ## Description A heap buffer overflow due to missing size checking in the property buffer when parsing PCF files in libXfont2 ComputeScaledProperties() before libXfont2 before 2.0.8 could be used by attackers using authenticated X clients to execute code within the X server. ## Where it's fixed | Platform | Product | Fixed in | Fix | Released | |---|---|---|---|---| | Linux | libXfont2 RHEL 10 | 2.0.6-5.el10_0.1 | [RHSA-2026:51061](https://patchblox.com/security/data/fix/linux/rhsa-2026-51061.md) | Jul 31, 2026 | | Linux | libXfont2 RHEL 8 | 0:2.0.3-2.el8_10.1 | [RHSA-2026:47103](https://patchblox.com/security/data/fix/linux/rhsa-2026-47103.md) | Jul 31, 2026 | | Linux | libXfont2 RHEL 9 | 0:2.0.3-12.el9_8.1 | [RHSA-2026:47084](https://patchblox.com/security/data/fix/linux/rhsa-2026-47084.md) | Aug 5, 2026 | | Linux | libXfont2 almalinux 10 | 2.0.6-5.el10_2.1 | [ALSA-2026:47079](https://patchblox.com/security/data/fix/linux/alsa-2026-47079.md) | Jul 28, 2026 | | Linux | libXfont2 almalinux 8 | 2.0.3-2.el8_10.1 | [ALSA-2026:47103](https://patchblox.com/security/data/fix/linux/alsa-2026-47103.md) | Jul 28, 2026 | | Linux | libXfont2 almalinux 9 | 2.0.3-12.el9_8.1 | [ALSA-2026:47084](https://patchblox.com/security/data/fix/linux/alsa-2026-47084.md) | Jul 28, 2026 | | Linux | libXfont2 amzn 2023 | 2.0.7-1.amzn2023.0.2 | [ALAS2023-2026-1967](https://patchblox.com/security/data/fix/linux/alas2023-2026-1967.md) | Jul 20, 2026 | | Linux | libXfont2 ol 8 | 0:2.0.3-2.el8_10.1 | [ELSA-2026-47103](https://patchblox.com/security/data/fix/linux/elsa-2026-47103.md) | Jul 28, 2026 | | Linux | libXfont2 opensuse-leap 16.0 | 2.0.7-160000.4.1 | [OPENSUSE-SU-2026:21284-1](https://patchblox.com/security/data/fix/linux/opensuse-su-2026-21284-1.md) | Jul 10, 2026 | | Linux | libXfont2 rocky 8 | 0:2.0.3-2.el8_10.1 | [RLSA-2026:47103](https://patchblox.com/security/data/fix/linux/rlsa-2026-47103.md) | Jul 29, 2026 | | Linux | libXfont2 sles 15.6 | 2.0.3-150000.3.3.1 | [SUSE-SU-2026:2794-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2794-1.md) | Jul 8, 2026 | | Linux | libXfont2 sles 15.7 | 2.0.3-150000.3.3.1 | [SUSE-SU-2026:2794-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-2794-1.md) | Jul 8, 2026 | | Linux | libXfont2 sles 16.0 | 2.0.7-160000.4.1 | [SUSE-SU-2026:22614-1](https://patchblox.com/security/data/fix/linux/suse-su-2026-22614-1.md) | Jul 10, 2026 | | Linux | libXfont2-debuginfo amzn 2023 | 2.0.7-1.amzn2023.0.2 | [ALAS2023-2026-1967](https://patchblox.com/security/data/fix/linux/alas2023-2026-1967.md) | Jul 20, 2026 | | Linux | libXfont2-debugsource amzn 2023 | 2.0.7-1.amzn2023.0.2 | [ALAS2023-2026-1967](https://patchblox.com/security/data/fix/linux/alas2023-2026-1967.md) | Jul 20, 2026 | | Linux | libXfont2-devel RHEL 8 | 0:2.0.3-2.el8_10.1 | [RHSA-2026:47103](https://patchblox.com/security/data/fix/linux/rhsa-2026-47103.md) | Jul 31, 2026 | | Linux | libXfont2-devel RHEL 9 | 0:2.0.3-12.el9_8.1 | [RHSA-2026:47084](https://patchblox.com/security/data/fix/linux/rhsa-2026-47084.md) | Aug 5, 2026 | | Linux | libXfont2-devel almalinux 10 | 2.0.6-5.el10_2.1 | [ALSA-2026:47079](https://patchblox.com/security/data/fix/linux/alsa-2026-47079.md) | Jul 28, 2026 | | Linux | libXfont2-devel almalinux 8 | 2.0.3-2.el8_10.1 | [ALSA-2026:47103](https://patchblox.com/security/data/fix/linux/alsa-2026-47103.md) | Jul 28, 2026 | | Linux | libXfont2-devel almalinux 9 | 2.0.3-12.el9_8.1 | [ALSA-2026:47084](https://patchblox.com/security/data/fix/linux/alsa-2026-47084.md) | Jul 28, 2026 | | Linux | libXfont2-devel amzn 2023 | 2.0.7-1.amzn2023.0.2 | [ALAS2023-2026-1967](https://patchblox.com/security/data/fix/linux/alas2023-2026-1967.md) | Jul 20, 2026 | | Linux | libXfont2-devel ol 8 | 0:2.0.3-2.el8_10.1 | [ELSA-2026-47103](https://patchblox.com/security/data/fix/linux/elsa-2026-47103.md) | Jul 28, 2026 | | Linux | libxfont Debian 12.15 (bookworm) | 1:2.0.6-1+deb12u1 | [DEBIAN-CVE-2026-56003](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56003.md) | Jul 13, 2026 | | Linux | libxfont Debian 13.5 (trixie) | 1:2.0.6-1+deb13u1 | [DEBIAN-CVE-2026-56003](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56003.md) | Jul 13, 2026 | | Linux | libxfont Debian 14 | 1:2.0.8-1 | [DEBIAN-CVE-2026-56003](https://patchblox.com/security/data/fix/linux/debian-cve-2026-56003.md) | Jul 13, 2026 | | Linux | libxfont2 Ubuntu 18.04.6 LTS (bionic) | 1:2.0.3-1ubuntu0.1~esm2 | [libxfont2 1:2.0.3-1ubuntu0.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-bionic-libxfont2-1-2.0.3-1ubuntu0.1-esm2.md) | Jul 23, 2026 | | Linux | libxfont2 Ubuntu 20.04 LTS (focal) | 1:2.0.3-1ubuntu0.20.04.1~esm2 | [libxfont2 1:2.0.3-1ubuntu0.20.04.1~esm2](https://patchblox.com/security/data/fix/linux/ubuntu-focal-libxfont2-1-2.0.3-1ubuntu0.20.04.1-esm2.md) | Jul 23, 2026 | | Linux | libxfont2 Ubuntu 22.04.1 LTS (jammy) | 1:2.0.5-1ubuntu0.2 | [libxfont2 1:2.0.5-1ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-jammy-libxfont2-1-2.0.5-1ubuntu0.2.md) | Jul 23, 2026 | | Linux | libxfont2 Ubuntu 24.04.5 LTS (noble) | 1:2.0.6-1+deb13u1build0.24.04.2 | [libxfont2 1:2.0.6-1+deb13u1build0.24.04.2](https://patchblox.com/security/data/fix/linux/ubuntu-noble-libxfont2-1-2.0.6-1-deb13u1build0.24.04.2.md) | Jul 23, 2026 | | Linux | libxfont2 Ubuntu 26.04.1 LTS (resolute) | 1:2.0.6-2ubuntu0.2 | [libxfont2 1:2.0.6-2ubuntu0.2](https://patchblox.com/security/data/fix/linux/ubuntu-resolute-libxfont2-1-2.0.6-2ubuntu0.2.md) | Jul 8, 2026 | --- Data as of 2026-11-08T13:06:02Z UTC. 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