Red Hat Product Errata RHSA-2026:49516 - Security Advisory Issued: 2026-08-03 Updated: 2026-08-03 RHSA-2026:49516 - 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 9.4 Update Services for SAP Solutions. 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 Server - AUS 9.4 x86_64 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 ppc64le Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 x86_64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 9.4 s390x Red Hat Enterprise Linux for x86_64 - Extended Life Cycle 9.4 x86_64 Red Hat Enterprise Linux for ARM 64 - Extended Life Cycle 9.4 aarch64 Red Hat Enterprise Linux for Power, little endian - Extended Life Cycle 9.4 ppc64le Red Hat Enterprise Linux for IBM z Systems - Extended Life Cycle 9.4 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 Server - AUS 9.4 SRPM xorg-x11-server-1.20.11-29.el9_4.1.src.rpm SHA-256: a7e90b126df947a0106f1d5367b902e7bdccd78dea75a6a256f3568a418a94f1 x86_64 xorg-x11-server-Xdmx-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 3f7416f6a8d52d5e70addc67cff60bbc65d2b49dcca06358b9e35e00f2b618cb xorg-x11-server-Xdmx-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: fb52bf7dca28701a5e770a6ec7e4ea4ede01731f4b616df033b26d52ba3a5980 xorg-x11-server-Xephyr-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 06d66c1b3bd503281177d3df23f4096396a5297790f962547a484dda69c2543b xorg-x11-server-Xephyr-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 4c30e20eb79ad0e57fe9941ccba82935eee338bb6cf10c3cd965f767f8eed28c xorg-x11-server-Xnest-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: e540cb280f63df33d065ac0d371e0078a7042d26db976c35771b96e44a3f7cc5 xorg-x11-server-Xnest-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: e0f6258ec807b99b9ad0d389d2872e9f1efea3c4f4dd525f994824af1a93d429 xorg-x11-server-Xorg-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 539c955a838ab7a00955ed9f0986181ab05a5dc1af4678747f0962e741cda1f1 xorg-x11-server-Xorg-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 49fcaee27d80e09225e66f6e3730baf16e7278a39ab32670c08e49ed2e129108 xorg-x11-server-Xvfb-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: dcfe1308298c7cad9c4673c9a60f9481d093608e7e9e96da96ad1d6b2b28801a xorg-x11-server-Xvfb-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: e2898db13eac14b02104f8994340945a5417fb8f8198ad1db86d1c2030f25bc0 xorg-x11-server-common-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 1a0c6f90aaa642fc8310d03099c9ce271ecb48caf39df2ae870cc7be8b585236 xorg-x11-server-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: ab75038d6ba91298f92245b7286a1b3de7e179a8478eca0e499a2a822707461b xorg-x11-server-debugsource-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 1b995a82dcc5846bc6934a950cfcf71d6a4a1af77cd6fbdf4e4aa6abd946e532 Red Hat Enterprise Linux Server for Power LE - Update Services for SAP Solutions 9.4 SRPM xorg-x11-server-1.20.11-29.el9_4.1.src.rpm SHA-256: a7e90b126df947a0106f1d5367b902e7bdccd78dea75a6a256f3568a418a94f1 ppc64le xorg-x11-server-Xdmx-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: 0e9a992e5240ec258a9318442cf87b65be10d04b5fb292aa22c41c244446c426 xorg-x11-server-Xdmx-debuginfo-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: 381bdeba3eb60c690dabee412bb954d467bfeff6780ace0aa40d4c3c68c24ff8 xorg-x11-server-Xephyr-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: f7f3827476c4b78a766da30fe56210d55f64f7f9ed7f6e8e3601bfe03126512e xorg-x11-server-Xephyr-debuginfo-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: 234fa587a433527fee00f522910bfef5f4e7e67c4c9fd6888058cc2c53e5e046 xorg-x11-server-Xnest-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: 8c03bfdb87890cd11a0f39dd652725f6998842a78443af82ff7bce85caa2b37f xorg-x11-server-Xnest-debuginfo-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: f8064a0a72155419e4f8dc96c54f67991eb544b86fb7df4631ae4577d1efd832 xorg-x11-server-Xorg-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: 50d2388f2a91650786c5e65a3649126bb0bd43164cddb22c7a26b91de0a447d6 xorg-x11-server-Xorg-debuginfo-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: 20ede3f94db1e6801e7f402fde7bee6eca6f4bc53169fdef60c997315c5a3671 xorg-x11-server-Xvfb-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: 4cbd6492068b1b69c44b12d540d4319ec36fdc615e317fb44cb12d074acbcb0e xorg-x11-server-Xvfb-debuginfo-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: ce4f50a624c4b885414aa16a0224c0abdba43efecebafb15d3bdd31dba2633a3 xorg-x11-server-common-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: 1a32cc7dc58dd39e67155cd11d3c85d8916eeae440ce0cad2d5bea29e5dc3a13 xorg-x11-server-debuginfo-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: e1ffb3c8dd8b64a2f88c7c8faa302a138e4ce47201c9878f0d3a5829a0db4d91 xorg-x11-server-debugsource-1.20.11-29.el9_4.1.ppc64le.rpm SHA-256: ea3c8ae947d37aea10856552694e013d52cfb3e0218d9e4a775c533851c26958 Red Hat Enterprise Linux for x86_64 - Update Services for SAP Solutions 9.4 SRPM xorg-x11-server-1.20.11-29.el9_4.1.src.rpm SHA-256: a7e90b126df947a0106f1d5367b902e7bdccd78dea75a6a256f3568a418a94f1 x86_64 xorg-x11-server-Xdmx-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 3f7416f6a8d52d5e70addc67cff60bbc65d2b49dcca06358b9e35e00f2b618cb xorg-x11-server-Xdmx-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: fb52bf7dca28701a5e770a6ec7e4ea4ede01731f4b616df033b26d52ba3a5980 xorg-x11-server-Xephyr-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 06d66c1b3bd503281177d3df23f4096396a5297790f962547a484dda69c2543b xorg-x11-server-Xephyr-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 4c30e20eb79ad0e57fe9941ccba82935eee338bb6cf10c3cd965f767f8eed28c xorg-x11-server-Xnest-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: e540cb280f63df33d065ac0d371e0078a7042d26db976c35771b96e44a3f7cc5 xorg-x11-server-Xnest-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: e0f6258ec807b99b9ad0d389d2872e9f1efea3c4f4dd525f994824af1a93d429 xorg-x11-server-Xorg-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 539c955a838ab7a00955ed9f0986181ab05a5dc1af4678747f0962e741cda1f1 xorg-x11-server-Xorg-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 49fcaee27d80e09225e66f6e3730baf16e7278a39ab32670c08e49ed2e129108 xorg-x11-server-Xvfb-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: dcfe1308298c7cad9c4673c9a60f9481d093608e7e9e96da96ad1d6b2b28801a xorg-x11-server-Xvfb-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: e2898db13eac14b02104f8994340945a5417fb8f8198ad1db86d1c2030f25bc0 xorg-x11-server-common-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 1a0c6f90aaa642fc8310d03099c9ce271ecb48caf39df2ae870cc7be8b585236 xorg-x11-server-debuginfo-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: ab75038d6ba91298f92245b7286a1b3de7e179a8478eca0e499a2a822707461b xorg-x11-server-debugsource-1.20.11-29.el9_4.1.x86_64.rpm SHA-256: 1b995a82dcc5846bc6934a950cfcf71d6a4a1af77cd6fbdf4e4aa6abd946e532 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 9.4 SRPM xorg-x11-server-1.20.11-29.el9_4.1.src.rpm SHA-256: a7e90b126df947a0106f1d5367b902e7bdccd78dea75a6a256f3568a418a94f1 aarch64 xorg-x11-server-Xdmx-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 82edd8833183cd572f84da262d342e05ab68d405e59835a484ebdec8a3a3967e xorg-x11-server-Xdmx-debuginfo-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: de2b8a161dabdf7d78f31d936f79fca3a9b71143e670ec0fa1528bed70e9ec04 xorg-x11-server-Xephyr-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 5f4eaa448aef9a0d4319fbbc166fd05d717c4bcb955c207f4c2a4ff2c428aedd xorg-x11-server-Xephyr-debuginfo-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: c75b9e5c1908a7f26de22e8f3d23ee678dd76a20059e871153d75f999990c537 xorg-x11-server-Xnest-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 7161ecd87ceb1d109fb7f8cc6f6e06e5ab00fdbfca032501a09bb6e2acac3d72 xorg-x11-server-Xnest-debuginfo-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 35b9905def8e13f2aea77741957b043077a030413d9c11410f8e982bc25603ad xorg-x11-server-Xorg-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 8780a38fcd32037184cc8cf26c03e43244cc6c43bc65c50867b817f8d84dbb8e xorg-x11-server-Xorg-debuginfo-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 9e748a5f9ab2b37c05fdc2909503765b02d68f649eeb7a65ce01ac3976262750 xorg-x11-server-Xvfb-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: bda18029874ea2531b998e827c929a2053773fd55f28143fb91622602c2c8328 xorg-x11-server-Xvfb-debuginfo-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 5716deec695f01dc6f2a749710c8f90d2ad974b80816463c0a030ec7a27dfe7f xorg-x11-server-common-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 1f60e51dde5142c7d3c6db54d497c2cca1c3450d57df48c8d821e7b2aac4e3db xorg-x11-server-debuginfo-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 6e2235cd39e85b3f4159a8b0b12f0fa29e18806a54dc765df8f52b86eaff1955 xorg-x11-server-debugsource-1.20.11-29.el9_4.1.aarch64.rpm SHA-256: 422da0451ea03aaa36ef715df09f291678c52d20028448370a6a35b853b1aaeb Red Hat Enterprise Linux for IBM z