{"id":"CVE-2026-50259","summary":"Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in xkb setmap request via mapwidths indexing","details":"A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. _XkbSetMapChecks() declares a fixed-size stack buffer mapWidths[256] indexed by key type index. The helper function CheckKeyTypes() writes to this buffer at a client-controlled offset, allowing a stack buffer overflow. This may be used to crash the server, or for privilege escalation if the X server runs as root.","modified":"2026-08-13T11:56:56.805716553Z","published":"2026-06-05T10:31:39.152Z","related":["ALSA-2026:26562","ALSA-2026:26566","ALSA-2026:26590","ALSA-2026:26610","ALSA-2026:26709","ALSA-2026:28923","ALSA-2026:29844"],"database_specific":{"cna_assigner":"redhat","cwe_ids":["CWE-121"],"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50259.json"},"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-2026-50259.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-2026-50259"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/50xxx/CVE-2026-50259.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-50259"},{"type":"REPORT","url":"https://bugzilla.redhat.com/show_bug.cgi?id=2485384"},{"type":"FIX","url":"https://gitlab.freedesktop.org/xorg/xserver/-/commit/867b59b33bee669cb412f1314e47c52eacf6e00b"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://gitlab.freedesktop.org/xorg/xserver","events":[{"introduced":"0"},{"fixed":"8570e9fcec845f68f0c90caa51fd7a24764ea220"},{"fixed":"af4b3d7250366e1a3822919e41fcf66da4966af2"},{"introduced":"0d7ec5c7d9b451066a079fe56bcc9722341a91ff"},{"fixed":"867b59b33bee669cb412f1314e47c52eacf6e00b"}],"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","xorg-server-1.19.99.903","xorg-server-1.19.99.902","xorg-server-1.19.99.901","xorg-server-1.19.0","xorg-server-1.18.99.902","xorg-server-1.18.99.901","xorg-server-1.18.99.2","xorg-server-1.18.0","xorg-server-1.17.99.902","xorg-server-1.17.99.901","xorg-server-1.17.0","xorg-server-1.16.99.902","xorg-server-1.16.99.901","xorg-server-1.16.0","xorg-server-1.15.99.904","xorg-server-1.15.99.903","xorg-server-1.15.99.902","xorg-server-1.15.99.901","xorg-server-1.15.0","xorg-server-1.14.99.905","xorg-server-1.14.99.904","xorg-server-1.14.99.903","xorg-server-1.14.99.902","xorg-server-1.14.99.901","xorg-server-1.14.99.3","xorg-server-1.14.99.2","xorg-server-1.14.99.1","xorg-server-1.14.0","xorg-server-1.13.99.902","xorg-server-1.13.99.901","xorg-server-1.13.0","xorg-server-1.12.99.905","xorg-server-1.12.99.904","xorg-server-1.12.99.903","xorg-server-1.12.99.902","xorg-server-1.12.99.901","xorg-server-1.12.0","xorg-server-1.11.99.903","xorg-server-1.11.99.902","xorg-server-1.11.99.901","xorg-server-1.11.99.1","xorg-server-1.11.0","xorg-server-1.10.99.902","xorg-server-1.10.99.901","xorg-server-1.10.0","xorg-server-1.9.99.903","xorg-server-1.9.99.902","xorg-server-1.9.99.901","xorg-server-1.9.0","xorg-server-1.8.99.906","xorg-server-1.8.99.905","xorg-server-1.8.99.904","xorg-server-1.8.99.903","xorg-server-1.8.99.902","xorg-server-1.8.99.901","xorg-server-1.8.0","xorg-server-1.7.99.902","xorg-server-1.7.99.901","xorg-server-1.7.99.2","xorg-server-1.7.99.1","xorg-server-1.6.99.901","xorg-server-1.6.99.900","xorg-server-1.5.99.1","xorg-server-1.1.99.3","xorg-server-1_1_99_2","xorg-server-1_0_99_901","XORG-7_0_99_901","xorg-server-1_1_99_1","xorg-server-1_0_99_2","xorg-server-1_0_99_1","XORG-7_0","pre-xgldrop-merge"],"database_specific":{"vanir_signatures":[{"signature_type":"Line","signature_version":"v1","source":"https://gitlab.freedesktop.org/xorg/xserver@867b59b33bee669cb412f1314e47c52eacf6e00b","target":{"file":"xkb/xkb.c"},"deprecated":false,"digest":{"line_hashes":["104192027045400740005368329079408994143","270443917615072931210725973900746555737","155951147083769541118935283931400369570","41502304825266828189393807211820093209"],"threshold":0.9},"id":"CVE-2026-50259-024cf00f"},{"digest":{"function_hash":"56310162544100721310076771059668596421","length":3710},"id":"CVE-2026-50259-79021e23","signature_type":"Function","signature_version":"v1","source":"https://gitlab.freedesktop.org/xorg/xserver@867b59b33bee669cb412f1314e47c52eacf6e00b","target":{"file":"xkb/xkb.c","function":"CheckKeyTypes"},"deprecated":false}],"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-50259.json","vanir_signatures_modified":"2026-08-12T16:25:37Z"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}