{"id":"RLSA-2026:26610","summary":"Important: xorg-x11-server security, bug fix, and enhancement update","details":"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.\n\nSecurity Fix(es):\n\n* 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)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in miSyncDestroyFence() (CVE-2026-50257)\n\n* 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)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: stack buffer overflow in XKB SetMap request via mapWidths indexing (CVE-2026-50259)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in FreeCounter() (CVE-2026-50260)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free in SyncChangeCounter() (CVE-2026-50261)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds read/write in GLX ChangeDrawableAttributes (CVE-2026-50262)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: use-after-free information disclosure in CreateSaverWindow() (CVE-2026-50263)\n\n* xorg-x11-server: xorg-x11-server-Xwayland: xorg-x11-server: out-of-bounds heap write in DRI2 DRIGetBuffers/DRIGetBuffersWithFormat (CVE-2026-50264)\n\nBug Fix(es) and Enhancement(s):\n\n* [xserver] Backport other security fixes without a CVE assigned [rhel-9.8.z] (JIRA:Rocky Linux-184288)\n\nFor 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.","modified":"2026-06-19T00:30:04.767763019Z","published":"2026-06-19T00:03:21.214998Z","upstream":["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":[{"type":"ADVISORY","url":"https://errata.rockylinux.org/RLSA-2026:26610"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485380"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485382"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485383"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485384"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485385"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485386"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485387"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485388"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485389"}],"affected":[{"package":{"name":"xorg-x11-server","ecosystem":"Rocky Linux:9","purl":"pkg:rpm/rocky-linux/xorg-x11-server?distro=rocky-linux-9&epoch=0"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"fixed":"0:1.20.11-34.el9_8.2"}],"database_specific":{"yum_repository":"AppStream"}}],"database_specific":{"source":"https://storage.googleapis.com/resf-osv-data/RLSA-2026:26610.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}],"credits":[{"name":"Rocky Enterprise Software Foundation"},{"name":"Red Hat"}]}