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libx11 — security advisory

Type: advisorySources: OSVAdvisory ID: UBUNTU-CVE-2026-94283

An out-of-bounds read vulnerability in libX11's XIM (X Input Method) attribute parser in libX11 before 1.8.14 could be used by malicious X servers to crash attached X clients.

Products
libx11
Affected versions
2:1.6.1-1ubuntu1, 2:1.6.1-1ubuntu2, 2:1.6.2-1ubuntu1, 2:1.6.2-1ubuntu2, 2:1.6.2-1ubuntu2.1, 2:1.6.2-1ubuntu2.1+esm1, 2:1.6.2-1ubuntu2.1+esm2, 2:1.6.2-1ubuntu2.1+esm3, 2:1.6.2-1ubuntu2.1+esm4, 2:1.6.2-1ubuntu2.1+esm5, 2:1.6.3-1ubuntu2, 2:1.6.3-1ubuntu2.1, 2:1.6.3-1ubuntu2.2, 2:1.6.3-1ubuntu2.2+esm1, 2:1.6.3-1ubuntu2.2+esm2, 2:1.6.3-1ubuntu2.2+esm3, 2:1.6.3-1ubuntu2.2+esm4, 2:1.6.4-3, 2:1.6.4-3ubuntu0.1, 2:1.6.4-3ubuntu0.2, 2:1.6.4-3ubuntu0.3, 2:1.6.4-3ubuntu0.4, 2:1.6.4-3ubuntu0.4+esm1, 2:1.6.4-3ubuntu0.4+esm2, 2:1.6.8-1, 2:1.6.9-2, 2:1.6.9-2ubuntu1, 2:1.6.9-2ubuntu1.1, 2:1.6.9-2ubuntu1.2, 2:1.6.9-2ubuntu1.5, 2:1.6.9-2ubuntu1.6, 2:1.7.2-1, 2:1.7.2-2, 2:1.7.2-2build1, 2:1.7.5-1, 2:1.7.5-1ubuntu0.2, 2:1.7.5-1ubuntu0.3, 2:1.8.12-1build1, 2:1.8.12-1build2, 2:1.8.13-1, 2:1.8.6-1ubuntu1, 2:1.8.7-1, 2:1.8.7-1build1
Fixed versions
2:1.6.2-1ubuntu2.1+esm6, 2:1.6.3-1ubuntu2.2+esm5, 2:1.6.4-3ubuntu0.4+esm3, 2:1.6.9-2ubuntu1.6+esm1, 2:1.7.5-1ubuntu0.4, 2:1.8.13-1ubuntu0.1, 2:1.8.7-1ubuntu0.1
CVEs
CVE-2026-94283
Confirmed fixed CVEs
Not specified
Updated in this feed
31 Oct 2026, 03:33 UTC · Revision 1

Source evidence

UBUNTU-CVE-2026-94283

core-osv · Original source

Published 28 Sept 2026, 09:17 UTC

An out-of-bounds read vulnerability in libX11's XIM (X Input Method) attribute parser in libX11 before 1.8.14 could be used by malicious X servers to crash attached X clients.

osv:UBUNTU-CVE-2026-94283

libx11

Fixed versions: 2:1.6.2-1ubuntu2.1+esm6

libx11

Fixed versions: 2:1.6.3-1ubuntu2.2+esm5

libx11

Fixed versions: 2:1.6.4-3ubuntu0.4+esm3

libx11

Fixed versions: 2:1.6.9-2ubuntu1.6+esm1

libx11

Fixed versions: 2:1.7.5-1ubuntu0.4

libx11

Fixed versions: 2:1.8.7-1ubuntu0.1

libx11

Fixed versions: Not specified

libx11

Fixed versions: 2:1.8.13-1ubuntu0.1

Complete source record
{
  "id": "f35d653dd90c15c0e6aac130f7fca1edd380ad10c580f5e9545f9c678c3db390",
  "url": "https://osv.dev/vulnerability/UBUNTU-CVE-2026-94283",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "UBUNTU-CVE-2026-94283",
    "summary": "An out-of-bounds read vulnerability in libX11's XIM (X Input Method) attribute parser in libX11 before 1.8.14 could be used by malicious X servers to crash attached X clients.",
    "evidence": "osv:UBUNTU-CVE-2026-94283",
    "products": [
      {
        "name": {
          "value": "libx11",
          "evidence": "/affected/0/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2:1.6.2-1ubuntu2.1+esm6",
            "evidence": "/affected/0/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2:1.6.1-1ubuntu1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.1-1ubuntu2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.2-1ubuntu1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.2-1ubuntu2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.2-1ubuntu2.1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.2-1ubuntu2.1+esm1",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.2-1ubuntu2.1+esm2",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.2-1ubuntu2.1+esm3",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.2-1ubuntu2.1+esm4",
            "evidence": "/affected/0/versions"
          },
          {
            "value": "2:1.6.2-1ubuntu2.1+esm5",
            "evidence": "/affected/0/versions"
          }
        ]
      },
      {
        "name": {
          "value": "libx11",
          "evidence": "/affected/1/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2:1.6.3-1ubuntu2.2+esm5",
            "evidence": "/affected/1/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2:1.6.3-1ubuntu2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2:1.6.3-1ubuntu2.1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2:1.6.3-1ubuntu2.2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2:1.6.3-1ubuntu2.2+esm1",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2:1.6.3-1ubuntu2.2+esm2",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2:1.6.3-1ubuntu2.2+esm3",
            "evidence": "/affected/1/versions"
          },
          {
            "value": "2:1.6.3-1ubuntu2.2+esm4",
            "evidence": "/affected/1/versions"
          }
        ]
      },
      {
        "name": {
          "value": "libx11",
          "evidence": "/affected/2/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2:1.6.4-3ubuntu0.4+esm3",
            "evidence": "/affected/2/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2:1.6.4-3",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2:1.6.4-3ubuntu0.1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2:1.6.4-3ubuntu0.2",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2:1.6.4-3ubuntu0.3",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2:1.6.4-3ubuntu0.4",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2:1.6.4-3ubuntu0.4+esm1",
            "evidence": "/affected/2/versions"
          },
          {
            "value": "2:1.6.4-3ubuntu0.4+esm2",
            "evidence": "/affected/2/versions"
          }
        ]
      },
      {
        "name": {
          "value": "libx11",
          "evidence": "/affected/3/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2:1.6.9-2ubuntu1.6+esm1",
            "evidence": "/affected/3/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2:1.6.8-1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "2:1.6.9-2",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "2:1.6.9-2ubuntu1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "2:1.6.9-2ubuntu1.1",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "2:1.6.9-2ubuntu1.2",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "2:1.6.9-2ubuntu1.5",
            "evidence": "/affected/3/versions"
          },
          {
            "value": "2:1.6.9-2ubuntu1.6",
            "evidence": "/affected/3/versions"
          }
        ]
      },
      {
        "name": {
          "value": "libx11",
          "evidence": "/affected/4/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2:1.7.5-1ubuntu0.4",
            "evidence": "/affected/4/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2:1.7.2-1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "2:1.7.2-2",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "2:1.7.2-2build1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "2:1.7.5-1",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "2:1.7.5-1ubuntu0.2",
            "evidence": "/affected/4/versions"
          },
          {
            "value": "2:1.7.5-1ubuntu0.3",
            "evidence": "/affected/4/versions"
          }
        ]
      },
      {
        "name": {
          "value": "libx11",
          "evidence": "/affected/5/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2:1.8.7-1ubuntu0.1",
            "evidence": "/affected/5/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2:1.8.6-1ubuntu1",
            "evidence": "/affected/5/versions"
          },
          {
            "value": "2:1.8.7-1",
            "evidence": "/affected/5/versions"
          },
          {
            "value": "2:1.8.7-1build1",
            "evidence": "/affected/5/versions"
          }
        ]
      },
      {
        "name": {
          "value": "libx11",
          "evidence": "/affected/6/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [],
        "affected_versions": [
          {
            "value": "2:1.8.13-1",
            "evidence": "/affected/6/versions"
          }
        ]
      },
      {
        "name": {
          "value": "libx11",
          "evidence": "/affected/7/package/name"
        },
        "prerequisites": [],
        "fixed_versions": [
          {
            "value": "2:1.8.13-1ubuntu0.1",
            "evidence": "/affected/7/ranges"
          }
        ],
        "affected_versions": [
          {
            "value": "2:1.8.12-1build1",
            "evidence": "/affected/7/versions"
          },
          {
            "value": "2:1.8.12-1build2",
            "evidence": "/affected/7/versions"
          },
          {
            "value": "2:1.8.13-1",
            "evidence": "/affected/7/versions"
          }
        ]
      }
    ],
    "severity": "medium",
    "structured": {
      "id": "UBUNTU-CVE-2026-94283",
      "aliases": [
        "UBUNTU-CVE-2026-94283"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:N/A:H"
        },
        {
          "type": "Ubuntu",
          "score": "medium"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2:1.6.2-1ubuntu2.1+esm6"
                }
              ]
            }
          ],
          "package": {
            "name": "libx11",
            "purl": "pkg:deb/ubuntu/libx11?arch=source&distro=esm-infra-legacy%2Ftrusty",
            "ecosystem": "Ubuntu:Pro:14.04:LTS"
          },
          "versions": [
            "2:1.6.1-1ubuntu1",
            "2:1.6.1-1ubuntu2",
            "2:1.6.2-1ubuntu1",
            "2:1.6.2-1ubuntu2",
            "2:1.6.2-1ubuntu2.1",
            "2:1.6.2-1ubuntu2.1+esm1",
            "2:1.6.2-1ubuntu2.1+esm2",
            "2:1.6.2-1ubuntu2.1+esm3",
            "2:1.6.2-1ubuntu2.1+esm4",
            "2:1.6.2-1ubuntu2.1+esm5"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-94283.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libx11-6",
                "binary_version": "2:1.6.2-1ubuntu2.1+esm6"
              },
              {
                "binary_name": "libx11-data",
                "binary_version": "2:1.6.2-1ubuntu2.1+esm6"
              },
              {
                "binary_name": "libx11-xcb1",
                "binary_version": "2:1.6.2-1ubuntu2.1+esm6"
              }
            ],
            "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2:1.6.3-1ubuntu2.2+esm5"
                }
              ]
            }
          ],
          "package": {
            "name": "libx11",
            "purl": "pkg:deb/ubuntu/libx11?arch=source&distro=esm-infra-legacy%2Fxenial",
            "ecosystem": "Ubuntu:Pro:16.04:LTS"
          },
          "versions": [
            "2:1.6.3-1ubuntu2",
            "2:1.6.3-1ubuntu2.1",
            "2:1.6.3-1ubuntu2.2",
            "2:1.6.3-1ubuntu2.2+esm1",
            "2:1.6.3-1ubuntu2.2+esm2",
            "2:1.6.3-1ubuntu2.2+esm3",
            "2:1.6.3-1ubuntu2.2+esm4"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-94283.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libx11-6",
                "binary_version": "2:1.6.3-1ubuntu2.2+esm5"
              },
              {
                "binary_name": "libx11-data",
                "binary_version": "2:1.6.3-1ubuntu2.2+esm5"
              },
              {
                "binary_name": "libx11-xcb1",
                "binary_version": "2:1.6.3-1ubuntu2.2+esm5"
              }
            ],
            "availability": "Available with Ubuntu Pro with Legacy support add-on: https://ubuntu.com/pro"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2:1.6.4-3ubuntu0.4+esm3"
                }
              ]
            }
          ],
          "package": {
            "name": "libx11",
            "purl": "pkg:deb/ubuntu/libx11?arch=source&distro=esm-infra%2Fbionic",
            "ecosystem": "Ubuntu:Pro:18.04:LTS"
          },
          "versions": [
            "2:1.6.4-3",
            "2:1.6.4-3ubuntu0.1",
            "2:1.6.4-3ubuntu0.2",
            "2:1.6.4-3ubuntu0.3",
            "2:1.6.4-3ubuntu0.4",
            "2:1.6.4-3ubuntu0.4+esm1",
            "2:1.6.4-3ubuntu0.4+esm2"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-94283.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libx11-6",
                "binary_version": "2:1.6.4-3ubuntu0.4+esm3"
              },
              {
                "binary_name": "libx11-data",
                "binary_version": "2:1.6.4-3ubuntu0.4+esm3"
              },
              {
                "binary_name": "libx11-xcb1",
                "binary_version": "2:1.6.4-3ubuntu0.4+esm3"
              }
            ],
            "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2:1.6.9-2ubuntu1.6+esm1"
                }
              ]
            }
          ],
          "package": {
            "name": "libx11",
            "purl": "pkg:deb/ubuntu/libx11?arch=source&distro=esm-infra%2Ffocal",
            "ecosystem": "Ubuntu:Pro:20.04:LTS"
          },
          "versions": [
            "2:1.6.8-1",
            "2:1.6.9-2",
            "2:1.6.9-2ubuntu1",
            "2:1.6.9-2ubuntu1.1",
            "2:1.6.9-2ubuntu1.2",
            "2:1.6.9-2ubuntu1.5",
            "2:1.6.9-2ubuntu1.6"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-94283.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libx11-6",
                "binary_version": "2:1.6.9-2ubuntu1.6+esm1"
              },
              {
                "binary_name": "libx11-data",
                "binary_version": "2:1.6.9-2ubuntu1.6+esm1"
              },
              {
                "binary_name": "libx11-xcb1",
                "binary_version": "2:1.6.9-2ubuntu1.6+esm1"
              }
            ],
            "availability": "Available with Ubuntu Pro (Infra-only): https://ubuntu.com/pro"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2:1.7.5-1ubuntu0.4"
                }
              ]
            }
          ],
          "package": {
            "name": "libx11",
            "purl": "pkg:deb/ubuntu/libx11?arch=source&distro=jammy",
            "ecosystem": "Ubuntu:22.04:LTS"
          },
          "versions": [
            "2:1.7.2-1",
            "2:1.7.2-2",
            "2:1.7.2-2build1",
            "2:1.7.5-1",
            "2:1.7.5-1ubuntu0.2",
            "2:1.7.5-1ubuntu0.3"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-94283.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libx11-6",
                "binary_version": "2:1.7.5-1ubuntu0.4"
              },
              {
                "binary_name": "libx11-data",
                "binary_version": "2:1.7.5-1ubuntu0.4"
              },
              {
                "binary_name": "libx11-xcb1",
                "binary_version": "2:1.7.5-1ubuntu0.4"
              }
            ],
            "availability": "No subscription required"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2:1.8.7-1ubuntu0.1"
                }
              ]
            }
          ],
          "package": {
            "name": "libx11",
            "purl": "pkg:deb/ubuntu/libx11?arch=source&distro=noble",
            "ecosystem": "Ubuntu:24.04:LTS"
          },
          "versions": [
            "2:1.8.6-1ubuntu1",
            "2:1.8.7-1",
            "2:1.8.7-1build1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-94283.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libx11-6",
                "binary_version": "2:1.8.7-1ubuntu0.1"
              },
              {
                "binary_name": "libx11-data",
                "binary_version": "2:1.8.7-1ubuntu0.1"
              },
              {
                "binary_name": "libx11-xcb1",
                "binary_version": "2:1.8.7-1ubuntu0.1"
              }
            ],
            "availability": "No subscription required"
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                }
              ]
            }
          ],
          "package": {
            "name": "libx11",
            "purl": "pkg:deb/ubuntu/libx11?arch=source&distro=stonking",
            "ecosystem": "Ubuntu:26.10"
          },
          "versions": [
            "2:1.8.13-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-94283.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libx11-6",
                "binary_version": "2:1.8.13-1"
              },
              {
                "binary_name": "libx11-data",
                "binary_version": "2:1.8.13-1"
              },
              {
                "binary_name": "libx11-xcb1",
                "binary_version": "2:1.8.13-1"
              }
            ]
          }
        },
        {
          "ranges": [
            {
              "type": "ECOSYSTEM",
              "events": [
                {
                  "introduced": "0"
                },
                {
                  "fixed": "2:1.8.13-1ubuntu0.1"
                }
              ]
            }
          ],
          "package": {
            "name": "libx11",
            "purl": "pkg:deb/ubuntu/libx11?arch=source&distro=resolute",
            "ecosystem": "Ubuntu:26.04:LTS"
          },
          "versions": [
            "2:1.8.12-1build1",
            "2:1.8.12-1build2",
            "2:1.8.13-1"
          ],
          "database_specific": {
            "source": "https://github.com/canonical/ubuntu-security-notices/blob/main/osv/cve/2026/UBUNTU-CVE-2026-94283.json"
          },
          "ecosystem_specific": {
            "binaries": [
              {
                "binary_name": "libx11-6",
                "binary_version": "2:1.8.13-1ubuntu0.1"
              },
              {
                "binary_name": "libx11-data",
                "binary_version": "2:1.8.13-1ubuntu0.1"
              },
              {
                "binary_name": "libx11-xcb1",
                "binary_version": "2:1.8.13-1ubuntu0.1"
              }
            ],
            "availability": "No subscription required"
          }
        }
      ],
      "modified": "2026-10-17T13:01:18.945629950Z",
      "provider": "osv",
      "upstream": [
        "CVE-2026-94283"
      ],
      "references": [
        "https://ubuntu.com/security/CVE-2026-94283",
        "https://www.cve.org/CVERecord?id=CVE-2026-94283",
        "https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/310",
        "https://gitlab.freedesktop.org/xorg/lib/libx11/-/merge_requests/310/diffs?commit_id=42d0303f243002a9856c76060569a61893c670dd",
        "https://ubuntu.com/security/notices/USN-8913-1"
      ]
    },
    "related_cves": [
      {
        "value": "CVE-2026-94283",
        "evidence": "/upstream"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 361643,
  "published_at": "2026-09-28T09:17:00+00:00"
}