xorg-x11-server-Xwayland: Fix of 8 CVEs

{
  "id": "4c10dcac54ae40244de2eeab7c1f5035f37ad1642709943da029065f13970953",
  "url": "https://osv.dev/vulnerability/CLSA-2026-1782484404",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "xorg-x11-server-Xwayland: Fix of 8 CVEs",
    "summary": "- CVE-2026-50256: increase XLFDMAXFONTNAMELEN and add bounds checks in doListFontsAndAliases/doListFontsWithInfo to prevent stack buffer overflow via long fonts.alias targets - CVE-2026-50257: fix use-after-free in miSyncDestroyFence by using safe list iteration and null-checking pTrigger before dereferencing - CVE-2026-50258: reject XkbSetMap key types with numLevels exceeding XkbMaxShiftLevel to prevent stack buffer overflow in XkbKeyTypesForCoreSymbols - CVE-2026-50259: clamp nMaps to XkbMaxLegalKeyCode+1 in CheckKeyTypes to prevent stack buffer overflow when XkbSetMapResizeTypes wraps - CVE-2026-50260: fix use-after-free in FreeCounter by using safe list iteration, advancing list head before callback, and NULL-ing out shared trigger pointers in FreeAwait - CVE-2026-50261: restart trigger list iteration in SyncChangeCounter after TriggerFired to avoid dereferencing freed sibling-trigger nodes - CVE-2026-50262: fix reversed length check in GLX ChangeDrawableAttributes by using REQUEST_FIXED_SIZE to prevent out-of-bounds read/write - CVE-2026-50263: re-fetch screen private after CheckScreenPrivate in CreateSaverWindow to avoid use-after-free on saver-window replacement",
    "evidence": "osv:CLSA-2026-1782484404",
    "products": [
      {
        "name": {
          "value": "xorg-x11-server-Xwayland",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "21.1.3-7.el9.tuxcare.els16",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": []
      },
      {
        "name": {
          "value": "xorg-x11-server-Xwayland-devel",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "21.1.3-7.el9.tuxcare.els16",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": []
      }
    ],
    "severity": "unknown",
    "structured": {
      "id": "CLSA-2026-1782484404",
      "aliases": [
        "CLSA-2026-1782484404"
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "21.1.3-7.el9.tuxcare.els16"
                }
              ]
            }
          ],
          "package": {
            "name": "xorg-x11-server-Xwayland",
            "purl": "pkg:rpm/tuxcare/xorg-x11-server-Xwayland?distro=almalinux-9.2",
            "ecosystem": "TuxCare:AlmaLinux:9.2"
          },
          "database_specific": {
            "source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782484404.json"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "21.1.3-7.el9.tuxcare.els16"
                }
              ]
            }
          ],
          "package": {
            "name": "xorg-x11-server-Xwayland-devel",
            "purl": "pkg:rpm/tuxcare/xorg-x11-server-Xwayland-devel?distro=almalinux-9.2",
            "ecosystem": "TuxCare:AlmaLinux:9.2"
          },
          "database_specific": {
            "source": "https://github.com/cloudlinux/tuxcare-osv/tree/main/data/els_os/almalinux9.2esu/CLSA-2026-1782484404.json"
          }
        }
      ],
      "modified": "2026-10-26T09:30:23.293487544Z",
      "provider": "osv",
      "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"
      ],
      "references": [
        "https://errata.tuxcare.com/els_os/almalinux9.2esu/CLSA-2026-1782484404.html",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50256",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50257",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50258",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50259",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50260",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50261",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50262",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-50263"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-50256",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-50257",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-50258",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-50259",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-50260",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-50261",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-50262",
        "evidence": "/upstream"
      },
      {
        "value": "CVE-2026-50263",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": null
  },
  "source_id": "core-osv",
  "document_id": 447009,
  "published_at": "2026-06-26T14:33:49+00:00"
}