{
  "affected": [
    {
      "ranges": [
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "2026.1.0-latest"
              },
              {
                "fixed": "2026.1.2"
              }
            ]
          },
          "events": [
            {
              "introduced": "322d3c0ac6a8f133b3f82875e9dbbe310f638c1b"
            },
            {
              "fixed": "808b2ac23d8ff421563b40203091026732471c60"
            }
          ],
          "repo": "https://github.com/discourse/discourse",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "2026.2.0-latest"
              },
              {
                "fixed": "2026.2.1"
              }
            ]
          },
          "events": [
            {
              "introduced": "f7cec86997edc21d6074ceb7666f7e2e6e1b1fdf"
            },
            {
              "fixed": "f38464e46df1b8c51f7d60826502476908d6bb2b"
            }
          ],
          "repo": "https://github.com/discourse/discourse",
          "type": "GIT"
        },
        {
          "database_specific": {
            "versions": [
              {
                "introduced": "0"
              },
              {
                "last_affected": "= 2026.3.0-latest"
              }
            ]
          },
          "events": [
            {
              "introduced": "0"
            },
            {
              "last_affected": "896e810e1b296478bba91559a8fc89a9926f11fe"
            }
          ],
          "repo": "https://github.com/discourse/discourse",
          "type": "GIT"
        }
      ]
    }
  ],
  "aliases": [
    "GHSA-2m5j-6v2r-cq2h"
  ],
  "database_specific": {
    "cna_assigner": "GitHub_M",
    "cwe_ids": [
      "CWE-863"
    ],
    "osv_generated_from": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33410.json"
  },
  "details": "Discourse is an open-source discussion platform. Versions prior to 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 have two authorization issues in the chat direct message API. First, when creating a direct message channel or adding users to an existing one, the `target_groups` parameter was passed directly to the user resolution query without checking group or member visibility for the acting user. An authenticated chat user could craft an API request with a known private/hidden group name and receive a channel containing that group's members, leaking their identities. Second, `can_chat?` only checked group membership, not the `chat_enabled` user preference. A chat-disabled user could create or query DM channels between other users via the direct messages API, potentially exposing private `last_message` content from the serialized channel response. Versions 2026.3.0-latest.1, 2026.2.1, and 2026.1.2 contain a patch. No known workarounds are available.",
  "id": "CVE-2026-33410",
  "modified": "2026-04-01T23:08:23.269851474Z",
  "published": "2026-03-19T21:57:27.176Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/33xxx/CVE-2026-33410.json"
    },
    {
      "type": "ADVISORY",
      "url": "https://github.com/discourse/discourse/security/advisories/GHSA-2m5j-6v2r-cq2h"
    },
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-33410"
    }
  ],
  "schema_version": "1.7.3",
  "severity": [
    {
      "score": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:N",
      "type": "CVSS_V3"
    }
  ],
  "summary": "Discourse hardens chat DM channel creation and expansion"
}