Red Hat Product Errata RHSA-2026:38487 - Security Advisory Issued: 2026-07-13 Updated: 2026-07-13 RHSA-2026:38487 - Security Advisory Overview Updated Packages Synopsis Important: xorg-x11-server security update Type/Severity Security Advisory: Important Red Hat Lightspeed patch analysis Identify and remediate systems affected by this advisory. View affected systems Topic An update for xorg-x11-server is now available for Red Hat Enterprise Linux 8. Red Hat Product Security has rated this update as having a security impact of Important. A Common Vulnerability Scoring System (CVSS) base score, which gives a detailed severity rating, is available for each vulnerability from the CVE link(s) in the References section. Description X.Org is an open-source implementation of the X Window System. It provides the basic low-level functionality that full-fledged graphical user interfaces are designed upon. Security Fix(es): xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow (CVE-2026-55999) For more details about the security issue(s), including the impact, a CVSS score, acknowledgments, and other related information, refer to the CVE page(s) listed in the References section. Solution For details on how to apply this update, which includes the changes described in this advisory, refer to: https://access.redhat.com/articles/11258 Affected Products Red Hat Enterprise Linux for x86_64 8 x86_64 Red Hat Enterprise Linux for IBM z Systems 8 s390x Red Hat Enterprise Linux for Power, little endian 8 ppc64le Red Hat Enterprise Linux for ARM 64 8 aarch64 Red Hat CodeReady Linux Builder for x86_64 8 x86_64 Red Hat CodeReady Linux Builder for Power, little endian 8 ppc64le Red Hat CodeReady Linux Builder for ARM 64 8 aarch64 Red Hat CodeReady Linux Builder for IBM z Systems 8 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 8.10 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 8.10 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 8.10 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 8.10 s390x Fixes BZ - 2496165 - CVE-2026-55999 xorg: X11: xserver: X.org: glamor Font Atlas Heap Buffer Overflow CVEs CVE-2026-55999 References https://access.redhat.com/security/updates/classification/#important Note: More recent versions of these packages may be available. Click a package name for more details. Red Hat Enterprise Linux for x86_64 8 SRPM xorg-x11-server-1.20.11-28.el8_10.3.src.rpm SHA-256: 3ffdec0530cae6ce800b5d49bd61586f1218d8bbd6d16986c24de8c9b9f805fc x86_64 xorg-x11-server-Xdmx-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: 603f0f34f970c97a87c662cad9608c756f52bc5fbb68879ce50eeaf11cb5a692 xorg-x11-server-Xdmx-debuginfo-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: fa9c3ac927f693afdd4a779bcaa3b506c1862ef53bf76d6e7c7b0117ce9563a7 xorg-x11-server-Xephyr-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: f3c0e945a2f9c832ae5828fde4aa90d670ce7d224c657fccba0e1c05dd100b25 xorg-x11-server-Xephyr-debuginfo-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: 5050e8d0aada5d99f430784f391697652019c74623b6a092c6f6b6e95eb221b2 xorg-x11-server-Xnest-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: e1a65fa0f366c99eb9666f3a212a5c41448e001bebc8a024d81a4fcc9e5e3b75 xorg-x11-server-Xnest-debuginfo-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: 52fdba42250345ecf75dc59077a6051e2dc776f9875e4bccef5ba05031f3dd4b xorg-x11-server-Xorg-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: be645dde16b9e53ad989177f6e5aa69feae3521c2084406c6afa66ecf18a2d45 xorg-x11-server-Xorg-debuginfo-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: 487756512666ea6bece907341db50cd8ca186f65339617d553461cb140840ea7 xorg-x11-server-Xvfb-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: a6f8c1b2aa8c8cfff3a1c887bcb3d24544f87a1a123f5e92124df85df129322a xorg-x11-server-Xvfb-debuginfo-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: 13106eafba1655168b6ede29ff481033f62aeb9cd682d3535c99d79daa4d90c0 xorg-x11-server-common-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: 9a93ee3747e37393e4271fb2866de09c27714c6035f8b831e924b03329d05e9a xorg-x11-server-debuginfo-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: 107a116e09905287c302891876ccb5145630491e2f359dab26ca44fe6e1d6ecd xorg-x11-server-debugsource-1.20.11-28.el8_10.3.x86_64.rpm SHA-256: 5e9f33da9eb577a05804bb9648adfc7e3eb9b3c0f204f06904053fbbb78ab70e Red Hat Enterprise Linux for IBM z Systems 8 SRPM xorg-x11-server-1.20.11-28.el8_10.3.src.rpm SHA-256: 3ffdec0530cae6ce800b5d49bd61586f1218d8bbd6d16986c24de8c9b9f805fc s390x xorg-x11-server-Xdmx-1.20.11-28.el8_10.3.s390x.rpm SHA-256: 9f2784d63a4ae97f313f4736ec9e0e8f4703deaa702812697347fda947c6c861 xorg-x11-server-Xdmx-debuginfo-1.20.11-28.el8_10.3.s390x.rpm SHA-256: ef43c60113be4d931d295b0567629891871ec03e96d11dad484783488c5e04f1 xorg-x11-server-Xephyr-1.20.11-28.el8_10.3.s390x.rpm SHA-256: fc897c899b0fbe5f0fadd37598c9bc67acacda568e617d986b41b65af2dc4887 xorg-x11-server-Xephyr-debuginfo-1.20.11-28.el8_10.3.s390x.rpm SHA-256: 828b9f4ce1b5d909fe0fe7e4a114f3711e5215da76ab346c7805d3abf2b36dc5 xorg-x11-server-Xnest-1.20.11-28.el8_10.3.s390x.rpm SHA-256: be6ec34da071880de589a165cee28df3a35314760a48d5413b9f45873b2fd582 xorg-x11-server-Xnest-debuginfo-1.20.11-28.el8_10.3.s390x.rpm SHA-256: f1716ae93138b1051f9a5c447fb69d47ca3985e8590e57084303ef0049950564 xorg-x11-server-Xorg-1.20.11-28.el8_10.3.s390x.rpm SHA-256: 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3ffdec0530cae6ce800b5d49bd61586f1218d8bbd6d16986c24de8c9b9f805fc ppc64le xorg-x11-server-Xdmx-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: 2581107cd9645aae288c0e8a254de86bb6c68a8e2249fcd51cad5919ae1947a6 xorg-x11-server-Xdmx-debuginfo-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: a41a57ef29ac6f0d172008a4582ebcb0e1d7ddb55a245c5a697bb2716c7aa0b8 xorg-x11-server-Xephyr-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: 47ef27ec07f2f74d50004e16865405e4bac65d7e4d966dd9c5e8c46a722f65b4 xorg-x11-server-Xephyr-debuginfo-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: 25abf06b651a57b80f2c0ebe78adb972d1bfc9737b880fd4be62923f623aef8a xorg-x11-server-Xnest-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: ab2478e9c5b35b88c76d679088ad582f3d808e9200e77bd36a1871caa09233d0 xorg-x11-server-Xnest-debuginfo-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: 1b211dd4627c118f5e324f4f6a4c762466dd0a66ab526783ecd2eddec791d79d xorg-x11-server-Xorg-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: 6583b30db703bae934d05434258069c6ea33cab241ddf2397204ab36aaca4211 xorg-x11-server-Xorg-debuginfo-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: aa228615e07a75e00b81f80718f4360870dd1cca6928e54c4e65b33d01d1b368 xorg-x11-server-Xvfb-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: f91d7e1e73a29d5243f23789fde235d62fefb08c917f2ffa2bb2a331026b7f54 xorg-x11-server-Xvfb-debuginfo-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: a07c62da0d48b8e0eca7a444ee01a835a140b0e62262f6096aae02718607ad7a xorg-x11-server-common-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: b85fcf5c5399ae2bfdfcf240afef53d7c6fae9eefa47ee5f09c0137a9584878a xorg-x11-server-debuginfo-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: 8fdf3a1f2bcb49b52f817871dbf8fccd711942c25d7f23303ca194f3a967435e xorg-x11-server-debugsource-1.20.11-28.el8_10.3.ppc64le.rpm SHA-256: b977fe9b7c4756af61c68de58a760d21ff79f785c49b3a05dc3be5e136b8a37c Red Hat Enterprise Linux for ARM 64 8 SRPM xorg-x11-server-1.20.11-28.el8_10.3.src.rpm SHA-256: 3ffdec0530cae6ce800b5d49bd61586f1218d8bbd6d16986c24de8c9b9f805fc aarch64 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