Vulnerability-Lookup

Vulnerability from bitnami_vulndb

Published

2026-06-16 12:37

Modified

2026-09-08 08:34

Summary

Discourse: Chat misauthorization and information disclosure

Details

Discourse is an open-source discussion platform. From versions 2026.1.0 to before 2026.1.4, 2026.3.0 to before 2026.3.1, and 2026.4.0 to before 2026.4.1, four authorization/disclosure issues in the chat plugin (one also involving discourse-calendar): read-only category users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel's current last_message (often unrelated DM content), and calendar event payloads exposed the attached chat channel and its last message to viewers without chat access (including anonymous users). This affects sites with the chat plugin enabled; the calendar issue additionally requires discourse-calendar. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0.

JSON

To clipboard

{
  "affected": [
    {
      "package": {
        "ecosystem": "Bitnami",
        "name": "discourse",
        "purl": "pkg:bitnami/discourse"
      },
      "ranges": [
        {
          "events": [
            {
              "introduced": "2026.1.0"
            },
            {
              "fixed": "2026.1.4"
            },
            {
              "introduced": "2026.3.0"
            },
            {
              "fixed": "2026.3.1"
            },
            {
              "introduced": "2026.4.0"
            },
            {
              "fixed": "2026.4.1"
            }
          ],
          "type": "SEMVER"
        }
      ],
      "severity": [
        {
          "score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
          "type": "CVSS_V3"
        }
      ]
    }
  ],
  "aliases": [
    "CVE-2026-45085"
  ],
  "database_specific": {
    "cpes": [
      "cpe:2.3:a:discourse:discourse:*:*:*:*:*:*:*:*"
    ],
    "severity": "Medium"
  },
  "details": "Discourse is an open-source discussion platform. From versions 2026.1.0 to before 2026.1.4, 2026.3.0 to before 2026.3.1, and 2026.4.0 to before 2026.4.1, four authorization/disclosure issues in the chat plugin (one also involving discourse-calendar): read-only category users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel\u0027s current last_message (often unrelated DM content), and calendar event payloads exposed the attached chat channel and its last message to viewers without chat access (including anonymous users). This affects sites with the chat plugin enabled; the calendar issue additionally requires discourse-calendar. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0.",
  "id": "BIT-discourse-2026-45085",
  "modified": "2026-09-08T08:34:36.952Z",
  "published": "2026-06-16T12:37:41.280Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://github.com/discourse/discourse/security/advisories/GHSA-rw8j-p2gv-q33w"
    },
    {
      "type": "WEB",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-45085"
    }
  ],
  "schema_version": "1.6.2",
  "summary": "Discourse: Chat misauthorization and information disclosure"
}

CVE-2026-45085 (GCVE-0-2026-45085)

Vulnerability from cvelistv5 – Published: 2026-06-12 20:25 – Updated: 2026-06-15 18:48

Title

Discourse: Chat misauthorization and information disclosure

Summary

Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, four authorization/disclosure issues in the chat plugin (one also involving discourse-calendar): read-only category users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel's current last_message (often unrelated DM content), and calendar event payloads exposed the attached chat channel and its last message to viewers without chat access (including anonymous users). This affects sites with the chat plugin enabled; the calendar issue additionally requires discourse-calendar. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1.

Severity

5.3 (Medium)


                        
                          CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N

SSVC

Exploitation: none Automatable: yes Technical Impact: partial

CISA Coordinator · CISA-ADP (v2.0.3)

Decision recorded 2026-06-15 18:45 UTC

CWE

CWE-862 - Missing Authorization
CWE-200 - Exposure of Sensitive Information to an Unauthorized Actor

Assigner

GitHub_M CNA under the mitre root

CNA scorecard C 72/100 over 7712 records in the last 180 days details

References

1 reference

URL	Tags
https://github.com/discourse/discourse/security/a…	x_refsource_CONFIRM

Impacted products

1 product

Vendor	Product	Version
discourse	discourse	Affected: >= 2026.1.0-latest, < 2026.1.4 Affected: >= 2026.3.0-latest, < 2026.3.1 Affected: >= 2026.4.0-latest, < 2026.4.1

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "adp": [
      {
        "metrics": [
          {
            "other": {
              "content": {
                "id": "CVE-2026-45085",
                "options": [
                  {
                    "Exploitation": "none"
                  },
                  {
                    "Automatable": "yes"
                  },
                  {
                    "Technical Impact": "partial"
                  }
                ],
                "role": "CISA Coordinator",
                "timestamp": "2026-06-15T18:45:55.268909Z",
                "version": "2.0.3"
              },
              "type": "ssvc"
            }
          }
        ],
        "providerMetadata": {
          "dateUpdated": "2026-06-15T18:48:50.661Z",
          "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
          "shortName": "CISA-ADP"
        },
        "title": "CISA ADP Vulnrichment"
      }
    ],
    "cna": {
      "affected": [
        {
          "product": "discourse",
          "vendor": "discourse",
          "versions": [
            {
              "status": "affected",
              "version": "\u003e= 2026.1.0-latest, \u003c 2026.1.4"
            },
            {
              "status": "affected",
              "version": "\u003e= 2026.3.0-latest, \u003c 2026.3.1"
            },
            {
              "status": "affected",
              "version": "\u003e= 2026.4.0-latest, \u003c 2026.4.1"
            }
          ]
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "value": "Discourse is an open-source discussion platform. From versions 2026.1.0-latest to before 2026.1.4, 2026.3.0-latest to before 2026.3.1, and 2026.4.0-latest to before 2026.4.1, four authorization/disclosure issues in the chat plugin (one also involving discourse-calendar): read-only category users could create chat threads, self-deleted chat messages could be restored by their author after channel access was revoked, moderators reviewing a flagged chat message were shown the channel\u0027s current last_message (often unrelated DM content), and calendar event payloads exposed the attached chat channel and its last message to viewers without chat access (including anonymous users). This affects sites with the chat plugin enabled; the calendar issue additionally requires discourse-calendar. This issue has been patched in versions 2026.1.4, 2026.3.1, 2026.4.1, and 2026.5.0-latest.1."
        }
      ],
      "metrics": [
        {
          "cvssV3_1": {
            "attackComplexity": "LOW",
            "attackVector": "NETWORK",
            "availabilityImpact": "NONE",
            "baseScore": 5.3,
            "baseSeverity": "MEDIUM",
            "confidentialityImpact": "LOW",
            "integrityImpact": "NONE",
            "privilegesRequired": "NONE",
            "scope": "UNCHANGED",
            "userInteraction": "NONE",
            "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:N/A:N",
            "version": "3.1"
          }
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-862",
              "description": "CWE-862: Missing Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        },
        {
          "descriptions": [
            {
              "cweId": "CWE-200",
              "description": "CWE-200: Exposure of Sensitive Information to an Unauthorized Actor",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-06-12T20:25:09.286Z",
        "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "shortName": "GitHub_M"
      },
      "references": [
        {
          "name": "https://github.com/discourse/discourse/security/advisories/GHSA-rw8j-p2gv-q33w",
          "tags": [
            "x_refsource_CONFIRM"
          ],
          "url": "https://github.com/discourse/discourse/security/advisories/GHSA-rw8j-p2gv-q33w"
        }
      ],
      "source": {
        "advisory": "GHSA-rw8j-p2gv-q33w",
        "discovery": "UNKNOWN"
      },
      "title": "Discourse: Chat misauthorization and information disclosure"
    }
  },
  "cveMetadata": {
    "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
    "assignerShortName": "GitHub_M",
    "cveId": "CVE-2026-45085",
    "datePublished": "2026-06-12T20:25:09.286Z",
    "dateReserved": "2026-05-08T18:45:10.097Z",
    "dateUpdated": "2026-06-15T18:48:50.661Z",
    "state": "PUBLISHED"
  },
  "dataType": "CVE_RECORD",
  "dataVersion": "5.2"
}

Sightings

Author	Source	Type	Date	Other

Nomenclature

Seen: The vulnerability was mentioned, discussed, or observed by the user.
Confirmed: The vulnerability has been validated from an analyst's perspective.
Published Proof of Concept: A public proof of concept is available for this vulnerability.
Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
Not confirmed: The user expressed doubt about the validity of the vulnerability.
Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.

Vulnerability timeline

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The MITRE ATT&CK techniques below are AI-generated suggestions, inferred from the description of the vulnerability by the CIRCL/vulnerability-attack-technique-classification-roberta-base model, served locally by ML-Gateway. They have not been verified by an analyst and are provided for guidance only.
The approach is described in our paper Mapping CVEs to MITRE ATT&CK Techniques: A Curated Gold-Set Classifier and the Limits of LLM-Assisted Label Expansion.
Browse all ATT&CK techniques and the vulnerabilities related to each.

Related by attack behaviour

Vulnerabilities whose description is nearest to this one in the vector space of the CIRCL/vulnerability-attack-technique-biencoder model. This is a similarity search over the bi-encoder space (plain cosine), not a classification, and it has no measured accuracy.

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