Red Hat Product Errata RHSA-2026:36798 - Security Advisory Issued: 2026-07-08 Updated: 2026-07-08 RHSA-2026:36798 - Security Advisory Overview Updated Packages Synopsis Important: xorg-x11-server-Xwayland 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-Xwayland is now available for Red Hat Enterprise Linux 10.0 Extended Update Support. 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 Xwayland is an X server for running X clients under Wayland. Security Fix(es): xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libXfont2 name length mismatch (CVE-2026-50256) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in miSyncDestroyFence() (CVE-2026-50257) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB key types due to unchecked shift levels (CVE-2026-50258) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB SetMap request via mapWidths indexing (CVE-2026-50259) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in FreeCounter() (CVE-2026-50260) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in SyncChangeCounter() (CVE-2026-50261) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds read/write in GLX ChangeDrawableAttributes (CVE-2026-50262) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free information disclosure in CreateSaverWindow() (CVE-2026-50263) xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds heap write in DRI2 DRIGetBuffers/DRIGetBuffersWithFormat (CVE-2026-50264) 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 - Extended Update Support 10.0 x86_64 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.0 s390x Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.0 ppc64le Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.0 aarch64 Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 10.0 x86_64 Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 10.0 ppc64le Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support 10.0 s390x Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 10.0 aarch64 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.0 aarch64 Red Hat Enterprise Linux for IBM z Systems - 4 years of updates 10.0 s390x Red Hat Enterprise Linux for Power, little endian - 4 years of support 10.0 ppc64le Red Hat Enterprise Linux for x86_64 - 4 years of updates 10.0 x86_64 Fixes BZ - 2485380 - CVE-2026-50256 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libXfont2 name length mismatch BZ - 2485382 - CVE-2026-50257 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in miSyncDestroyFence() BZ - 2485383 - CVE-2026-50258 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB key types due to unchecked shift levels BZ - 2485384 - CVE-2026-50259 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB SetMap request via mapWidths indexing BZ - 2485385 - CVE-2026-50260 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in FreeCounter() BZ - 2485386 - CVE-2026-50261 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in SyncChangeCounter() BZ - 2485387 - CVE-2026-50262 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds read/write in GLX ChangeDrawableAttributes BZ - 2485388 - CVE-2026-50263 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free information disclosure in CreateSaverWindow() BZ - 2485389 - CVE-2026-50264 xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds heap write in DRI2 DRIGetBuffers/DRIGetBuffersWithFormat CVEs CVE-2026-50256 CVE-2026-50257 CVE-2026-50258 CVE-2026-50259 CVE-2026-50260 CVE-2026-50261 CVE-2026-50262 CVE-2026-50263 CVE-2026-50264 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 - Extended Update Support 10.0 SRPM xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.src.rpm SHA-256: 165c8e612affb9e55328afff057441a95b7647c2fcedcb6b1ff03136c34abec2 x86_64 xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.x86_64.rpm SHA-256: d93f9a43c1c6f5a0f790c500da73b51f0150c21aefe008a06839c47a6dcaf7c2 xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.x86_64.rpm SHA-256: a6b6b03d2b413e23221c5646565751719b489dfdafb75fe67b7a9b1e083124ee xorg-x11-server-Xwayland-debugsource-24.1.5-6.el10_0.1.x86_64.rpm SHA-256: c98001064ccaf40c3970a3204fc3bc912754b660626e43c420e4c98b794bcbe5 Red Hat Enterprise Linux for IBM z Systems - Extended Update Support 10.0 SRPM xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.src.rpm SHA-256: 165c8e612affb9e55328afff057441a95b7647c2fcedcb6b1ff03136c34abec2 s390x xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.s390x.rpm SHA-256: 3b3ba1342057af6d58f5258e68bdba7b6727045a9bb615ebf43aa4e5e0ead52e xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.s390x.rpm SHA-256: 2e142f1be1464bb478d1d8655b9a220932ef7d7ac6425869ab8e509bb7422359 xorg-x11-server-Xwayland-debugsource-24.1.5-6.el10_0.1.s390x.rpm SHA-256: 3a03c9d385cf0c1b4ce8186516651d34dc86bc4c3335d9ad572c969710520b33 Red Hat Enterprise Linux for Power, little endian - Extended Update Support 10.0 SRPM xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.src.rpm SHA-256: 165c8e612affb9e55328afff057441a95b7647c2fcedcb6b1ff03136c34abec2 ppc64le xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.ppc64le.rpm SHA-256: 30b1d45eff7a9424019dd7543c95b19c5a678015220ac3cfc5977529561e7053 xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.ppc64le.rpm SHA-256: a9fd2698e88045b9e85771db4a376d2f8f8fe28002e28e857d38d735bfd2f7c5 xorg-x11-server-Xwayland-debugsource-24.1.5-6.el10_0.1.ppc64le.rpm SHA-256: b4011e4a643932bfd9f608c7a33a2d702f1f32c02b14c0b6d4ef3f29d6563224 Red Hat Enterprise Linux for ARM 64 - Extended Update Support 10.0 SRPM xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.src.rpm SHA-256: 165c8e612affb9e55328afff057441a95b7647c2fcedcb6b1ff03136c34abec2 aarch64 xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.aarch64.rpm SHA-256: 5615102fbaab5bc30b233d7e1015f98c42f6d98e56aa96fa9fe2449c7f0e4ab8 xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.aarch64.rpm SHA-256: d41b9f770c564ef7fd105f89354977c2ea446512da49fe60f17bf5c360d82cba xorg-x11-server-Xwayland-debugsource-24.1.5-6.el10_0.1.aarch64.rpm SHA-256: 982d745e91cb90cb7431fe9ccca9f29e54df09be3d768d93d0984979dd287314 Red Hat CodeReady Linux Builder for x86_64 - Extended Update Support 10.0 SRPM x86_64 xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.x86_64.rpm SHA-256: a6b6b03d2b413e23221c5646565751719b489dfdafb75fe67b7a9b1e083124ee xorg-x11-server-Xwayland-debugsource-24.1.5-6.el10_0.1.x86_64.rpm SHA-256: c98001064ccaf40c3970a3204fc3bc912754b660626e43c420e4c98b794bcbe5 xorg-x11-server-Xwayland-devel-24.1.5-6.el10_0.1.x86_64.rpm SHA-256: 11f31acf75650b1b65aaa81e1966c807d2320cc48fe6faa6d70a16bbd793055e Red Hat CodeReady Linux Builder for Power, little endian - Extended Update Support 10.0 SRPM ppc64le xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.ppc64le.rpm SHA-256: a9fd2698e88045b9e85771db4a376d2f8f8fe28002e28e857d38d735bfd2f7c5 xorg-x11-server-Xwayland-debugsource-24.1.5-6.el10_0.1.ppc64le.rpm SHA-256: b4011e4a643932bfd9f608c7a33a2d702f1f32c02b14c0b6d4ef3f29d6563224 xorg-x11-server-Xwayland-devel-24.1.5-6.el10_0.1.ppc64le.rpm SHA-256: a0613491aaacc486f8b3a40390482a0c373f5458a69ed2ae704e31fc5813573a Red Hat CodeReady Linux Builder for IBM z Systems - Extended Update Support 10.0 SRPM s390x xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.s390x.rpm SHA-256: 2e142f1be1464bb478d1d8655b9a220932ef7d7ac6425869ab8e509bb7422359 xorg-x11-server-Xwayland-debugsource-24.1.5-6.el10_0.1.s390x.rpm SHA-256: 3a03c9d385cf0c1b4ce8186516651d34dc86bc4c3335d9ad572c969710520b33 xorg-x11-server-Xwayland-devel-24.1.5-6.el10_0.1.s390x.rpm SHA-256: 3b1cd0d709ffb5964fc9a0d727b94bd52f03d45321238e3fe8434d040d9b777c Red Hat CodeReady Linux Builder for ARM 64 - Extended Update Support 10.0 SRPM aarch64 xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.aarch64.rpm SHA-256: d41b9f770c564ef7fd105f89354977c2ea446512da49fe60f17bf5c360d82cba xorg-x11-server-Xwayland-debugsource-24.1.5-6.el10_0.1.aarch64.rpm SHA-256: 982d745e91cb90cb7431fe9ccca9f29e54df09be3d768d93d0984979dd287314 xorg-x11-server-Xwayland-devel-24.1.5-6.el10_0.1.aarch64.rpm SHA-256: f95e67293b2c3326eefbdaa9c907c518e9ec681cb996888d67c2f656563e18e4 Red Hat Enterprise Linux for ARM 64 - 4 years of updates 10.0 SRPM xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.src.rpm SHA-256: 165c8e612affb9e55328afff057441a95b7647c2fcedcb6b1ff03136c34abec2 aarch64 xorg-x11-server-Xwayland-24.1.5-6.el10_0.1.aarch64.rpm SHA-256: 5615102fbaab5bc30b233d7e1015f98c42f6d98e56aa96fa9fe2449c7f0e4ab8 xorg-x11-server-Xwayland-debuginfo-24.1.5-6.el10_0.1.aarch64.rpm SHA-256: d41b9f770c564ef7fd105f89354977c2ea446512da49fe60f17bf5c360d82