{"id":"CVE-2026-50260","summary":"Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: use-after-free in freecounter()","details":"A use-after-free flaw was found in the X.Org X server and Xwayland in FreeCounter(). A client that sets up multiple SyncCounters and awaits on those triggers can trigger a use-after-free when destroying those counters via a second client connection. This may be used to crash the server, or for privilege escalation if the X server runs as root.","modified":"2026-08-13T11:56:58.956424898Z","published":"2026-06-05T10:36:30.319Z","related":["ALSA-2026:26562","ALSA-2026:26566","ALSA-2026:26590","ALSA-2026:26610","ALSA-2026:26709","ALSA-2026:28923","ALSA-2026:29844"],"database_specific":{"cwe_ids":["CWE-416"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50260.json","cna_assigner":"redhat"},"references":[{"type":"WEB","url":"https://access.redhat.com/downloads/content/package-browser/"},{"type":"WEB","url":"https://lists.x.org/archives/xorg-announce/2026-June/003702.html"},{"type":"WEB","url":"https://redhat.atlassian.net/browse/PSIRTSUPT-16950"},{"type":"WEB","url":"https://security.access.redhat.com/data/csaf/v2/vex/2026/cve-2026-50260.json"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:26562"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:26566"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:26590"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:26610"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:26709"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:28923"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:29844"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36083"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36085"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36086"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36087"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36632"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36633"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36634"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36768"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36791"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36792"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:36798"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:38502"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:38810"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:46377"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:46382"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:46385"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:46392"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:46456"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:46460"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:46473"},{"type":"ADVISORY","url":"https://access.redhat.com/errata/RHSA-2026:49519"},{"type":"ADVISORY","url":"https://access.redhat.com/security/cve/CVE-2026-50260"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50260.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50260"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485385"},{"type":"FIX","url":"https://gitlab.freedesktop.org/xorg/xserver/-/commit/f5abfb61994471023d8c6470428c8e30c411cc0b"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://gitlab.freedesktop.org/xorg/xserver","events":[{"introduced":"0"},{"fixed":"8570e9fcec845f68f0c90caa51fd7a24764ea220"},{"fixed":"af4b3d7250366e1a3822919e41fcf66da4966af2"},{"introduced":"0d7ec5c7d9b451066a079fe56bcc9722341a91ff"},{"fixed":"f5abfb61994471023d8c6470428c8e30c411cc0b"}],"database_specific":{"cpe":["cpe:2.3:a:x.org:x_server:*:*:*:*:*:*:*:*","cpe:2.3:a:x.org:xwayland:*:*:*:*:*:*:*:*","cpe:2.3:o:redhat:enterprise_linux:7.0:*:*:*:*:*:*:*"],"extracted_events":[{"introduced":"0"},{"fixed":"21.1.23"},{"fixed":"24.1.12"},{"introduced":"7.0"},{"last_affected":"7.0"}],"source":["CPE_RANGE","CPE_STRING","REFERENCES"]}}],"versions":["7.0","xwayland-24.1.11","xorg-server-21.1.22","xwayland-24.1.10","xwayland-24.1.9","xorg-server-21.1.21","xorg-server-21.1.20","xorg-server-21.1.19","xorg-server-21.1.18","xwayland-24.1.8","xwayland-24.1.7","xorg-server-21.1.17","xwayland-24.1.6","xorg-server-21.1.16","xwayland-24.1.5","xorg-server-21.1.15","xwayland-24.1.4","xorg-server-21.1.14","xwayland-24.1.3","xwayland-24.1.2","xwayland-24.1.1","xwayland-24.1.0","xwayland-24.0.99.902","xorg-server-21.1.13","xwayland-24.0.99.901","xorg-server-21.1.12","xorg-server-21.1.11","xorg-server-21.1.10","xorg-server-21.1.9","xorg-server-21.1.8","xorg-server-21.1.7","xorg-server-21.1.6","xorg-server-21.1.5","xorg-server-21.1.4","xorg-server-21.1.3","xorg-server-21.1.2","xorg-server-21.1.1","xorg-server-21.1.0","xorg-server-21.0.99.902","xorg-server-21.0.99.901","xorg-server-21.0.99.1","xorg-server-1.20.0","xorg-server-1.19.99.905","xorg-server-1.19.99.904",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