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Medium

Information Disclosure in Common Teams API

Type: advisorySources: OSV

Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams endpoint

Products
Not specified
Affected versions
Not specified
Fixed versions
Not specified
CVEs
CVE-2025-12559
Confirmed fixed CVEs
Not specified
Updated in this feed
4 Nov 2026, 15:07 UTC · Revision 1

Source evidence

Information Disclosure in Common Teams API

core-osv · Original source

Published 27 Nov 2025, 16:36 UTC

Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams endpoint

osv:CVE-2025-12559
Complete source record
{
  "id": "03a4f41046a9e96858606dcc72ccf1e01d29f0514a9713e7afc6f65e6af13a04",
  "url": "https://osv.dev/vulnerability/CVE-2025-12559",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "Information Disclosure in Common Teams API",
    "summary": "Mattermost versions 11.0.x <= 11.0.2, 10.12.x <= 10.12.1, 10.11.x <= 10.11.4, 10.5.x <= 10.5.12 fail to sanitize team email addresses to be visible only to Team Admins, which allows any authenticated user to view team email addresses via the GET /api/v4/channels/{channel_id}/common_teams endpoint",
    "evidence": "osv:CVE-2025-12559",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2025-12559",
      "aliases": [
        "CVE-2025-12559",
        "GHSA-4g87-9x45-cx2h",
        "GO-2025-4169"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:N/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/mattermost/mattermost",
              "type": "GIT",
              "events": [
                {
                  "introduced": "58bd34fd34cbd7d3da777d627b6cffdf8a532930"
                },
                {
                  "fixed": "288281e8cbf15260ad074b883a263b796cdb3e28"
                },
                {
                  "introduced": "5b955468ea1ea8b56c0fb10feb258a36a767d7bb"
                },
                {
                  "fixed": "46b5c436bb3093cc1da3fa2455f93d4c52389eee"
                },
                {
                  "introduced": "ba3dc1612ce8f37bf9814b1ea6364181fb5abd62"
                },
                {
                  "fixed": "364c2203de00fe0d8424b6b46d6f0eeb02a2539a"
                },
                {
                  "introduced": "0"
                },
                {
                  "fixed": "feb598ed2b7ac3cb78a253b032ad7e4628b0de00"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "10.5.0"
                      },
                      {
                        "fixed": "10.5.13"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "10.11.0"
                      },
                      {
                        "fixed": "10.11.5"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "10.12.0"
                      },
                      {
                        "fixed": "10.12.2"
                      }
                    ],
                    "source": "CPE_RANGE"
                  },
                  {
                    "cpe": "cpe:2.3:a:mattermost:mattermost_server:*:*:*:*:*:*:*:*",
                    "range": [
                      {
                        "introduced": "11.0.0"
                      },
                      {
                        "fixed": "11.0.3"
                      }
                    ],
                    "source": "CPE_RANGE"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v11.0.3-rc1",
            "v10.12.1",
            "v10.11.4-rc3",
            "v10.11.4",
            "v10.5.12",
            "v11.0.2",
            "v10.11.4-rc2",
            "v11.0.1-rc3",
            "v11.0.1",
            "v10.5.12-rc1",
            "v10.11.4-rc1",
            "v10.12.1-rc1",
            "v11.0.1-rc2",
            "v11.0.1-rc1",
            "v11.0.0-alpha.1",
            "v10.11.3",
            "server/public/v0.1.19",
            "v10.5.11",
            "server/public/v0.1.18",
            "v10.12.0",
            "mattermost-redux@10.12.0",
            "@mattermost/types@10.12.0",
            "@mattermost/client@10.12.0",
            "server/public/v0.1.17",
            "v10.11.2-rc2",
            "v10.11.2",
            "v10.5.11-rc1",
            "v10.11.2-rc1",
            "v10.5.10",
            "v10.11.1",
            "v10.5.10-rc2",
            "v10.11.1-rc1",
            "v10.11.0-rc3",
            "v10.11.0",
            "mattermost-redux@10.11.0",
            "@mattermost/types@10.11.0",
            "@mattermost/client@10.11.0",
            "v10.5.10-rc1",
            "server/public/v0.1.16",
            "v10.5.9",
            "v10.5.9-rc4",
            "v10.5.9-rc3",
            "v10.5.9-rc2",
            "preview-v0.1",
            "v10.5.9-rc1",
            "v10.5.8",
            "server/public/v0.1.15",
            "v10.5.8-rc1",
            "server/public/v0.1.14",
            "v10.5.7",
            "v10.5.6-rc1",
            "v10.5.6",
            "server/public/v0.1.13",
            "v10.5.5",
            "server/public/v0.1.12",
            "v10.5.5-rc1",
            "v10.5.4-rc2",
            "v10.5.4",
            "v10.5.4-rc1",
            "v10.5.3",
            "v10.5.3-rc1",
            "server/public/v0.1.11",
            "v10.5.2",
            "v10.5.1",
            "v10.5.1-rc2",
            "v10.5.1-rc1",
            "v10.5.0-rc6",
            "v10.5.0",
            "@mattermost/types@10.5.0",
            "@mattermost/client@10.5.0",
            "server/public/v0.1.10",
            "server/public/v0.1.9",
            "server/public/v0.1.8",
            "server/public/v0.1.7",
            "server/public/v0.1.6",
            "server/public/v0.1.5",
            "server/public/v0.1.4",
            "server/public/v0.1.3",
            "server/public/v0.1.2",
            "server/public/v0.1.1",
            "server/public/v0.1.0",
            "server/public/v0.0.18",
            "server/public/v0.0.17",
            "server/public/v0.0.16",
            "server/public/v0.0.15",
            "server/public/v0.0.14",
            "server/public/v0.0.13",
            "server/public/v0.0.12",
            "server/public/v0.0.11",
            "server/public/v0.0.10",
            "server/public/v0.0.9",
            "server/public/v0.0.8",
            "server/public/v0.0.7",
            "server/public/v0.0.6",
            "server/public/v0.0.5",
            "cloud-2022-11-24-1",
            "cloud-2022-11-11-1",
            "cloud-2022-10-06-1",
            "cloud-2022-09-08-1",
            "cloud-2022-08-10-1",
            "cloud-2022-07-20-1",
            "v5.2.0-rc2",
            "v5.2.0-rc1",
            "v5.1.0-rc1",
            "v5.0.0-rc1",
            "v4.10.0-rc1",
            "v4.9.0-rc1",
            "v4.8.0-rc1",
            "v4.7.0-rc1",
            "v4.6.0-rc2",
            "v4.6.0-rc1",
            "v4.5.0-rc1",
            "v4.4.0-rc1",
            "v4.3.0-rc1",
            "v4.2.0-rc1",
            "v0.5.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2025-12559.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:36.735108258Z",
      "provider": "osv",
      "references": [
        "https://mattermost.com/security-updates",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/12xxx/CVE-2025-12559.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2025-12559"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-200"
        ],
        "cna_assigner": "Mattermost",
        "unresolved_ranges": [
          {
            "extracted_events": [
              {
                "range": [
                  {
                    "introduced": "11.0.0"
                  },
                  {
                    "last_affected": "11.0.2"
                  },
                  {
                    "introduced": "10.12.0"
                  },
                  {
                    "last_affected": "10.12.1"
                  },
                  {
                    "introduced": "10.11.0"
                  },
                  {
                    "last_affected": "10.11.4"
                  },
                  {
                    "introduced": "10.5.0"
                  },
                  {
                    "last_affected": "10.5.12"
                  }
                ],
                "source": "AFFECTED_FIELD",
                "strategy": "StandardRange"
              }
            ]
          }
        ],
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2025/12xxx/CVE-2025-12559.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2025-12559",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 504001,
  "published_at": "2025-11-27T16:36:30.545+00:00"
}