data/osv/GO-2026-5838.json

{
  "schema_version": "1.3.1",
  "id": "GO-2026-5838",
  "modified": "0001-01-01T00:00:00Z",
  "published": "0001-01-01T00:00:00Z",
  "aliases": [
    "CVE-2026-5740",
    "GHSA-w9m8-p4cc-4qj9"
  ],
  "summary": "Mattermost doesn't properly validate msgpack-encoded WebSocket frames before memory allocation in github.com/mattermost/mattermost-server",
  "details": "Mattermost doesn't properly validate msgpack-encoded WebSocket frames before memory allocation in github.com/mattermost/mattermost-server",
  "affected": [
    {
      "package": {
        "name": "github.com/mattermost/mattermost-server",
        "ecosystem": "Go"
      },
      "ranges": [
        {
          "type": "SEMVER",
          "events": [
            {
              "introduced": "10.11.0+incompatible"
            },
            {
              "fixed": "10.11.15+incompatible"
            },
            {
              "introduced": "11.4.0+incompatible"
            },
            {
              "fixed": "11.4.5+incompatible"
            },
            {
              "introduced": "11.5.0+incompatible"
            },
            {
              "fixed": "11.5.4+incompatible"
            },
            {
              "introduced": "11.6.0+incompatible"
            },
            {
              "fixed": "11.6.1+incompatible"
            }
          ]
        }
      ],
      "ecosystem_specific": {}
    },
    {
      "package": {
        "name": "github.com/mattermost/mattermost-server/v5",
        "ecosystem": "Go"
      },
      "ranges": [
        {
          "type": "SEMVER",
          "events": [
            {
              "introduced": "0"
            }
          ]
        }
      ],
      "ecosystem_specific": {}
    },
    {
      "package": {
        "name": "github.com/mattermost/mattermost-server/v6",
        "ecosystem": "Go"
      },
      "ranges": [
        {
          "type": "SEMVER",
          "events": [
            {
              "introduced": "0"
            }
          ]
        }
      ],
      "ecosystem_specific": {}
    },
    {
      "package": {
        "name": "github.com/mattermost/mattermost/server/v8",
        "ecosystem": "Go"
      },
      "ranges": [
        {
          "type": "SEMVER",
          "events": [
            {
              "introduced": "0"
            },
            {
              "fixed": "8.0.0-20260410202636-17939826efa2"
            }
          ]
        }
      ],
      "ecosystem_specific": {}
    }
  ],
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/advisories/GHSA-w9m8-p4cc-4qj9"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-5740"
    },
    {
      "type": "WEB",
      "url": "https://github.com/mattermost/mattermost/commit/17939826efa20a97f087b3d390ec5136df350bae"
    },
    {
      "type": "WEB",
      "url": "https://mattermost.com/security-updates"
    }
  ],
  "database_specific": {
    "url": "https://pkg.go.dev/vuln/GO-2026-5838",
    "review_status": "UNREVIEWED"
  }
}