MaxKB: Chat share-link endpoint missing owner check: a chat token can publish another user's conversation

{
  "id": "1775bdf1f6edcb0fff94a55e3f5e67bfc9b09f14e73640292ba37febab0172fc",
  "url": "https://osv.dev/vulnerability/CVE-2026-79917",
  "method": "structured",
  "payload": {
    "kind": "advisory",
    "title": "MaxKB: Chat share-link endpoint missing owner check: a chat token can publish another user's conversation",
    "summary": "MaxKB is an open-source AI assistant for enterprise. In 2.7.0 through 2.10.4-lts, POST /chat/api/{application_id}/chat/{chat_id}/share_chat verifies that a conversation exists but does not verify that it belongs to the authenticated chat_user_id or to the application bound to the caller's token. An attacker with any chat token and a known victim chat_id can create an unauthenticated public ChatShareLink exposing the victim's conversation and can create PublicFileAccess state that makes associated files retrievable without credentials, with no available revoke path. No fixed version is available as of this review.",
    "evidence": "osv:CVE-2026-79917",
    "products": [],
    "severity": "medium",
    "structured": {
      "id": "CVE-2026-79917",
      "aliases": [
        "CVE-2026-79917",
        "GHSA-m8gr-554p-8r82"
      ],
      "metrics": [
        {
          "type": "CVSS_V3",
          "score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N"
        }
      ],
      "affected": [
        {
          "ranges": [
            {
              "repo": "https://github.com/1panel-dev/maxkb",
              "type": "GIT",
              "events": [
                {
                  "introduced": "15b1466c75a31e5d4d1bd812e047bfd898b5046a"
                },
                {
                  "last_affected": "fd6141e662582e88a41edbb7f6f89f4539e3e5dd"
                }
              ],
              "database_specific": {
                "extracted_events": [
                  {
                    "range": [
                      {
                        "introduced": "2.7.0"
                      },
                      {
                        "last_affected": "2.10.4-lts"
                      }
                    ],
                    "source": "AFFECTED_FIELD",
                    "strategy": "StringRangeExpression"
                  },
                  {
                    "range": [
                      {
                        "introduced": "2.7.0"
                      },
                      {
                        "last_affected": "2.10.4-lts"
                      }
                    ],
                    "source": "DESCRIPTION"
                  }
                ]
              }
            }
          ],
          "versions": [
            "v2.10.4-lts",
            "v2.10.2-lts",
            "v2.10.0-lts",
            "v2.9.2",
            "v2.9.1",
            "v2.9.0",
            "v2.8.1",
            "v2.8.0",
            "v2.7.0"
          ],
          "database_specific": {
            "source": "https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-79917.json"
          }
        }
      ],
      "modified": "2026-10-28T02:30:51.854811612Z",
      "provider": "osv",
      "references": [
        "https://github.com/1Panel-dev/MaxKB/security/advisories/GHSA-m8gr-554p-8r82",
        "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79917.json",
        "https://nvd.nist.gov/vuln/detail/CVE-2026-79917"
      ],
      "provider_metadata": {
        "cwe_ids": [
          "CWE-285",
          "CWE-639"
        ],
        "cna_assigner": "GitHub_M",
        "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/79xxx/CVE-2026-79917.json"
      }
    },
    "related_cves": [
      {
        "value": "CVE-2026-79917",
        "evidence": "/id"
      }
    ],
    "security_relevant": true,
    "severity_evidence": "/severity/0/score"
  },
  "source_id": "core-osv",
  "document_id": 520334,
  "published_at": "2026-09-21T20:43:27.292+00:00"
}