{"id":"CVE-2025-26595","title":"A buffer overflow flaw was found in X.Org and Xwayland","summary":"A buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buf…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-121","CWE-787"],"vendor":"tigervnc","product":"tigervnc","affected":["tigervnc","x_server < 21.1.16","xwayland < 24.1.6","enterprise_linux = 7.0","enterprise_linux = 8.0","enterprise_linux = 9.0"],"patched":["x_server 21.1.16","xwayland 24.1.6"],"published":"2025-02-25","updated":"2026-06-25","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2025-26595","references":[{"url":"https://access.redhat.com/errata/RHSA-2025:2500","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2502","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2861","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2862","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2865","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2866","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2873","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2874","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2875","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2879","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:2880","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:3976","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:7163","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:7165","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/errata/RHSA-2025:7458","label":"secalert@redhat.com"},{"url":"https://access.redhat.com/security/cve/CVE-2025-26595","label":"secalert@redhat.com"},{"url":"https://bugzilla.redhat.com/show_bug.cgi?id=2345257","label":"secalert@redhat.com"},{"url":"https://lists.debian.org/debian-lts-announce/2025/02/msg00036.html","label":"af854a3a-2127-422b-91ae-364da2661108"}],"tags":["nvd"],"epss":0.00438,"epssPercentile":0.37513,"ingestedAt":"2026-06-29T13:24:34.166Z","slug":"CVE-2025-26595","body":"## Overview\n\nA buffer overflow flaw was found in X.Org and Xwayland. The code in XkbVModMaskText() allocates a fixed-sized buffer on the stack and copies the names of the virtual modifiers to that buffer. The code fails to check the bounds of the buffer and would copy the data regardless of the size.\n\n## Affected\n\n- `tigervnc`\n- `x_server < 21.1.16`\n- `xwayland < 24.1.6`\n- `enterprise_linux = 7.0`\n- `enterprise_linux = 8.0`\n- `enterprise_linux = 9.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `x_server 21.1.16`\n- `xwayland 24.1.6`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0.1,"exploitation":0,"ransomware":0},"changes":[]}