UnratedFix available

DEBIAN-CVE-2026-50260

Type: advisorySource: OSV1 source record

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.

Announced 5 Jun 2026Source revision 1

Original source ↗

DEBIAN-CVE-2026-50260

Primary source · Revision 1

Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.

Security context

Source reference: osv:DEBIAN-CVE-2026-50260

xorg-server

Source reference: /affected/0/package/name

Affected versions: 2:21.1.7-3
Source reference: /affected/0/versions
2:21.1.7-3+deb12u1
Source reference: /affected/0/versions
2:21.1.7-3+deb12u10
Source reference: /affected/0/versions
2:21.1.7-3+deb12u11
Source reference: /affected/0/versions
2:21.1.7-3+deb12u12
Source reference: /affected/0/versions
2:21.1.7-3+deb12u2
Source reference: /affected/0/versions
2:21.1.7-3+deb12u3
Source reference: /affected/0/versions
2:21.1.7-3+deb12u4
Source reference: /affected/0/versions
2:21.1.7-3+deb12u5
Source reference: /affected/0/versions
2:21.1.7-3+deb12u6
Source reference: /affected/0/versions
2:21.1.7-3+deb12u7
Source reference: /affected/0/versions
2:21.1.7-3+deb12u8
Source reference: /affected/0/versions
2:21.1.7-3+deb12u9
Source reference: /affected/0/versions
Fixed versions: 2:21.1.7-3+deb12u13
Source reference: /affected/0/ranges
Prerequisites: Not stated in this record

xorg-server

Source reference: /affected/1/package/name

Affected versions: 2:21.1.16-1.3
Source reference: /affected/1/versions
2:21.1.16-1.3+deb13u1
Source reference: /affected/1/versions
2:21.1.16-1.3+deb13u2
Source reference: /affected/1/versions
Fixed versions: 2:21.1.16-1.3+deb13u3
Source reference: /affected/1/ranges
Prerequisites: Not stated in this record

xorg-server

Source reference: /affected/2/package/name

Affected versions: 2:21.1.16-1.3
Source reference: /affected/2/versions
2:21.1.18-1
Source reference: /affected/2/versions
2:21.1.18-2
Source reference: /affected/2/versions
2:21.1.20-1
Source reference: /affected/2/versions
2:21.1.21-1
Source reference: /affected/2/versions
2:21.1.22-1
Source reference: /affected/2/versions
Fixed versions: 2:21.1.23-1
Source reference: /affected/2/ranges
Prerequisites: Not stated in this record

xwayland

Source reference: /affected/3/package/name

Affected versions: 2:22.1.9-1
Source reference: /affected/3/versions
2:23.1.0-1
Source reference: /affected/3/versions
2:23.1.1-1
Source reference: /affected/3/versions
2:23.2.0-1
Source reference: /affected/3/versions
2:23.2.1-1
Source reference: /affected/3/versions
2:23.2.2-1
Source reference: /affected/3/versions
2:23.2.3-1
Source reference: /affected/3/versions
2:23.2.4-1
Source reference: /affected/3/versions
2:23.2.6-1
Source reference: /affected/3/versions
2:24.0.99.901-1
Source reference: /affected/3/versions
2:24.1.0-1
Source reference: /affected/3/versions
2:24.1.10-1
Source reference: /affected/3/versions
2:24.1.11-1
Source reference: /affected/3/versions
2:24.1.12-1
Source reference: /affected/3/versions
2:24.1.13-1
Source reference: /affected/3/versions
2:24.1.2-1
Source reference: /affected/3/versions
2:24.1.3-1
Source reference: /affected/3/versions
2:24.1.4-1
Source reference: /affected/3/versions
2:24.1.4-2
Source reference: /affected/3/versions
2:24.1.4-3
Source reference: /affected/3/versions
2:24.1.5-1
Source reference: /affected/3/versions
2:24.1.6-1
Source reference: /affected/3/versions
2:24.1.8-1
Source reference: /affected/3/versions
2:24.1.9-1
Source reference: /affected/3/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

xwayland

Source reference: /affected/4/package/name

Affected versions: 2:24.1.10-1
Source reference: /affected/4/versions
2:24.1.11-1
Source reference: /affected/4/versions
2:24.1.12-1
Source reference: /affected/4/versions
2:24.1.13-1
Source reference: /affected/4/versions
2:24.1.6-1
Source reference: /affected/4/versions
2:24.1.8-1
Source reference: /affected/4/versions
2:24.1.9-1
Source reference: /affected/4/versions
Fixed versions: Not stated in this record
Prerequisites: Not stated in this record

xwayland

Source reference: /affected/5/package/name

Affected versions: 2:24.1.10-1
Source reference: /affected/5/versions
2:24.1.11-1
Source reference: /affected/5/versions
2:24.1.6-1
Source reference: /affected/5/versions
2:24.1.8-1
Source reference: /affected/5/versions
2:24.1.9-1
Source reference: /affected/5/versions
Fixed versions: 2:24.1.12-1
Source reference: /affected/5/ranges
Prerequisites: Not stated in this record

Structured affected-version data

Original package identities and version rules from this source.

[
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "2:21.1.7-3+deb12u13"
          }
        ]
      }
    ],
    "package": {
      "name": "xorg-server",
      "purl": "pkg:deb/debian/xorg-server?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "2:21.1.7-3",
      "2:21.1.7-3+deb12u1",
      "2:21.1.7-3+deb12u10",
      "2:21.1.7-3+deb12u11",
      "2:21.1.7-3+deb12u12",
      "2:21.1.7-3+deb12u2",
      "2:21.1.7-3+deb12u3",
      "2:21.1.7-3+deb12u4",
      "2:21.1.7-3+deb12u5",
      "2:21.1.7-3+deb12u6",
      "2:21.1.7-3+deb12u7",
      "2:21.1.7-3+deb12u8",
      "2:21.1.7-3+deb12u9"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50260.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "2:21.1.16-1.3+deb13u3"
          }
        ]
      }
    ],
    "package": {
      "name": "xorg-server",
      "purl": "pkg:deb/debian/xorg-server?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "2:21.1.16-1.3",
      "2:21.1.16-1.3+deb13u1",
      "2:21.1.16-1.3+deb13u2"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50260.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "2:21.1.23-1"
          }
        ]
      }
    ],
    "package": {
      "name": "xorg-server",
      "purl": "pkg:deb/debian/xorg-server?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "2:21.1.16-1.3",
      "2:21.1.18-1",
      "2:21.1.18-2",
      "2:21.1.20-1",
      "2:21.1.21-1",
      "2:21.1.22-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50260.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "xwayland",
      "purl": "pkg:deb/debian/xwayland?arch=source&distro=bookworm",
      "ecosystem": "Debian:12"
    },
    "versions": [
      "2:22.1.9-1",
      "2:23.1.0-1",
      "2:23.1.1-1",
      "2:23.2.0-1",
      "2:23.2.1-1",
      "2:23.2.2-1",
      "2:23.2.3-1",
      "2:23.2.4-1",
      "2:23.2.6-1",
      "2:24.0.99.901-1",
      "2:24.1.0-1",
      "2:24.1.10-1",
      "2:24.1.11-1",
      "2:24.1.12-1",
      "2:24.1.13-1",
      "2:24.1.2-1",
      "2:24.1.3-1",
      "2:24.1.4-1",
      "2:24.1.4-2",
      "2:24.1.4-3",
      "2:24.1.5-1",
      "2:24.1.6-1",
      "2:24.1.8-1",
      "2:24.1.9-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50260.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          }
        ]
      }
    ],
    "package": {
      "name": "xwayland",
      "purl": "pkg:deb/debian/xwayland?arch=source&distro=trixie",
      "ecosystem": "Debian:13"
    },
    "versions": [
      "2:24.1.10-1",
      "2:24.1.11-1",
      "2:24.1.12-1",
      "2:24.1.13-1",
      "2:24.1.6-1",
      "2:24.1.8-1",
      "2:24.1.9-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50260.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  },
  {
    "ranges": [
      {
        "type": "ECOSYSTEM",
        "events": [
          {
            "introduced": "0"
          },
          {
            "fixed": "2:24.1.12-1"
          }
        ]
      }
    ],
    "package": {
      "name": "xwayland",
      "purl": "pkg:deb/debian/xwayland?arch=source&distro=forky",
      "ecosystem": "Debian:14"
    },
    "versions": [
      "2:24.1.10-1",
      "2:24.1.11-1",
      "2:24.1.6-1",
      "2:24.1.8-1",
      "2:24.1.9-1"
    ],
    "database_specific": {
      "source": "https://storage.googleapis.com/debian-osv/debian-cve-osv/DEBIAN-CVE-2026-50260.json"
    },
    "ecosystem_specific": {
      "urgency": "not yet assigned"
    }
  }
]

Publisher severity

No explicit severity was provided.

Event: #57263 · Revision 1
Added to Heist Feed: Sun, 25 Oct 2026 17:06:43 GMT
Publisher date: Fri, 05 Jun 2026 12:16:39 GMT

Read the original announcement