rlsa-2026:26590
Vulnerability from osv_rocky
Published
2026-06-19 00:03
Modified
2026-07-03 00:06
Summary
Important: xorg-x11-server-Xwayland security, bug fix, and enhancement update
Details

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)

Bug Fix(es) and Enhancement(s):

  • [xwayland] Backport other security fixes without a CVE assigned [rhel-9.8.z] (JIRA:Rocky Linux-184292)

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.

Severity
7.8 (High)
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Credits
Rocky Enterprise Software Foundation
Red Hat
References
To clipboard 

{
  "affected": [
    {
      "package": {
        "ecosystem": "Rocky Linux:9",
        "name": "xorg-x11-server-Xwayland",
        "purl": "pkg:rpm/rocky-linux/xorg-x11-server-Xwayland?distro=rocky-linux-9\u0026epoch=0"
      },
      "ranges": [
        {
          "database_specific": {
            "yum_repository": "AppStream"
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "0:24.1.9-4.el9_8.2"
            }
          ],
          "type": "ECOSYSTEM"
        }
      ]
    }
  ],
  "credits": [
    {
      "name": "Rocky Enterprise Software Foundation"
    },
    {
      "name": "Red Hat"
    }
  ],
  "details": "Xwayland is an X server for running X clients under Wayland.\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* [xwayland] Backport other security fixes without a CVE assigned [rhel-9.8.z] (JIRA:Rocky Linux-184292)\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.",
  "id": "RLSA-2026:26590",
  "modified": "2026-07-03T00:06:28.226302Z",
  "published": "2026-06-19T00:03:21.214998Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://errata.rockylinux.org/RLSA-2026:26590"
    },
    {
      "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"
    }
  ],
  "schema_version": "1.7.0",
  "severity": [
    {
      "score": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Important: xorg-x11-server-Xwayland security, bug fix, and enhancement update",
  "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"
  ]
}



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