Vulnerability-Lookup

GHSA-4PV3-XJC8-WFM8

Vulnerability from github – Published: 2026-09-04 09:32 – Updated: 2026-09-04 09:32

Details

An authorization flaw in MISP allowed an authenticated user to submit a sharing_group_id without verifying that the user was authorized to use the referenced Sharing Group.

In several attribute and Galaxy Cluster creation and editing workflows, validation of the submitted Sharing Group was performed only when the request explicitly set the distribution field to 4 ("Sharing Group"). An attacker could therefore craft a request containing a sharing_group_id while omitting the distribution parameter, or otherwise avoiding the distribution == 4 condition, causing the Sharing Group authorization check to be skipped.

This could allow a user with permission to create or modify the affected MISP objects to associate data with a Sharing Group that they are not authorized to use. Depending on the affected object's existing distribution settings and subsequent processing, this could bypass intended information-sharing boundaries and result in unauthorized placement or distribution of data to members of another Sharing Group.

The issue affected attribute attachment and editing operations as well as Galaxy Cluster creation and editing. The fix ensures that authorization is performed whenever a non-empty sharing_group_id is submitted, independently of the distribution parameter. It also centralizes the authorization decision in SharingGroup::canUse() and explicitly rejects empty Sharing Group identifiers rather than allowing them to be interpreted as an unrestricted query.

Severity

7.6 (High)


                  
                    CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

Show details on source website

JSON

To clipboard

{
  "affected": [],
  "aliases": [
    "CVE-2026-85533"
  ],
  "database_specific": {
    "cwe_ids": [
      "CWE-862"
    ],
    "github_reviewed": false,
    "github_reviewed_at": null,
    "nvd_published_at": "2026-09-04T09:17:11Z",
    "severity": "HIGH"
  },
  "details": "An authorization flaw in MISP allowed an authenticated user to submit a sharing_group_id without verifying that the user was authorized to use the referenced Sharing Group.\n\nIn several attribute and Galaxy Cluster creation and editing workflows, validation of the submitted Sharing Group was performed only when the request explicitly set the distribution field to 4 (\"Sharing Group\"). An attacker could therefore craft a request containing a sharing_group_id while omitting the distribution parameter, or otherwise avoiding the distribution == 4 condition, causing the Sharing Group authorization check to be skipped.\n\nThis could allow a user with permission to create or modify the affected MISP objects to associate data with a Sharing Group that they are not authorized to use. Depending on the affected object\u0027s existing distribution settings and subsequent processing, this could bypass intended information-sharing boundaries and result in unauthorized placement or distribution of data to members of another Sharing Group.\n\nThe issue affected attribute attachment and editing operations as well as Galaxy Cluster creation and editing. The fix ensures that authorization is performed whenever a non-empty sharing_group_id is submitted, independently of the distribution parameter. It also centralizes the authorization decision in SharingGroup::canUse() and explicitly rejects empty Sharing Group identifiers rather than allowing them to be interpreted as an unrestricted query.",
  "id": "GHSA-4pv3-xjc8-wfm8",
  "modified": "2026-09-04T09:32:01Z",
  "published": "2026-09-04T09:32:01Z",
  "references": [
    {
      "type": "ADVISORY",
      "url": "https://nvd.nist.gov/vuln/detail/CVE-2026-85533"
    },
    {
      "type": "WEB",
      "url": "https://github.com/MISP/MISP/commit/9b1363955"
    }
  ],
  "schema_version": "1.4.0",
  "severity": [
    {
      "score": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X",
      "type": "CVSS_V4"
    }
  ]
}

CVE-2026-85533 (GCVE-0-2026-85533)

Vulnerability from cvelistv5 – Published: 2026-09-04 08:53 – Updated: 2026-09-04 08:53

Title

MISP Sharing Group Authorization Bypass via Omitted Distribution Parameter

Summary

An authorization flaw in MISP allowed an authenticated user to submit a sharing_group_id without verifying that the user was authorized to use the referenced Sharing Group. In several attribute and Galaxy Cluster creation and editing workflows, validation of the submitted Sharing Group was performed only when the request explicitly set the distribution field to 4 ("Sharing Group"). An attacker could therefore craft a request containing a sharing_group_id while omitting the distribution parameter, or otherwise avoiding the distribution == 4 condition, causing the Sharing Group authorization check to be skipped. This could allow a user with permission to create or modify the affected MISP objects to associate data with a Sharing Group that they are not authorized to use. Depending on the affected object's existing distribution settings and subsequent processing, this could bypass intended information-sharing boundaries and result in unauthorized placement or distribution of data to members of another Sharing Group. The issue affected attribute attachment and editing operations as well as Galaxy Cluster creation and editing. The fix ensures that authorization is performed whenever a non-empty sharing_group_id is submitted, independently of the distribution parameter. It also centralizes the authorization decision in SharingGroup::canUse() and explicitly rejects empty Sharing Group identifiers rather than allowing them to be interpreted as an unrestricted query.

Severity

7.6 (High)


                        
                          CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N

CWE

CWE-862 - Missing Authorization

Assigner

CIRCL ENISA root

References

1 reference

URL	Tags
https://github.com/MISP/MISP/commit/9b1363955	patch

Impacted products

1 product

Vendor	Product	Version
misp	misp	Affected: 0 , ≤ 2.5.45 (semver)

Credits

Andras Iklody (the Insomniac MISP lead dev) elhoim (David André) Claude Opus 5 (1M context)

Show details on NVD website

JSON

To clipboard

{
  "containers": {
    "cna": {
      "affected": [
        {
          "defaultStatus": "unaffected",
          "product": "misp",
          "repo": "https://github.com/MISP/MISP",
          "vendor": "misp",
          "versions": [
            {
              "lessThanOrEqual": "2.5.45",
              "status": "affected",
              "version": "0",
              "versionType": "semver"
            }
          ]
        }
      ],
      "credits": [
        {
          "lang": "en",
          "type": "remediation developer",
          "value": "Andras Iklody"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "elhoim (David Andr\u00e9)"
        },
        {
          "lang": "en",
          "type": "finder",
          "value": "Claude Opus 5 (1M context)"
        }
      ],
      "descriptions": [
        {
          "lang": "en",
          "supportingMedia": [
            {
              "base64": false,
              "type": "text/html",
              "value": "\u003cp\u003eAn authorization flaw in MISP allowed an authenticated user to submit a \u003ccode\u003esharing_group_id\u003c/code\u003e without verifying that the user was authorized to use the referenced Sharing Group.\u003c/p\u003e\u003cp\u003eIn several attribute and Galaxy Cluster creation and editing workflows, validation of the submitted Sharing Group was performed only when the request explicitly set the \u003ccode\u003edistribution\u003c/code\u003e field to \u003ccode\u003e4\u003c/code\u003e (\"Sharing Group\"). An attacker could therefore craft a request containing a \u003ccode\u003esharing_group_id\u003c/code\u003e while omitting the \u003ccode\u003edistribution\u003c/code\u003e parameter, or otherwise avoiding the \u003ccode\u003edistribution == 4\u003c/code\u003e condition, causing the Sharing Group authorization check to be skipped.\u003c/p\u003e\u003cp\u003eThis could allow a user with permission to create or modify the affected MISP objects to associate data with a Sharing Group that they are not authorized to use. Depending on the affected object\u0027s existing distribution settings and subsequent processing, this could bypass intended information-sharing boundaries and result in unauthorized placement or distribution of data to members of another Sharing Group.\u003c/p\u003e\u003cp\u003eThe issue affected attribute attachment and editing operations as well as Galaxy Cluster creation and editing. The fix ensures that authorization is performed whenever a non-empty \u003ccode\u003esharing_group_id\u003c/code\u003e is submitted, independently of the \u003ccode\u003edistribution\u003c/code\u003e parameter. It also centralizes the authorization decision in \u003ccode\u003eSharingGroup::canUse()\u003c/code\u003e and explicitly rejects empty Sharing Group identifiers rather than allowing them to be interpreted as an unrestricted query.\u003c/p\u003e"
            }
          ],
          "value": "An authorization flaw in MISP allowed an authenticated user to submit a sharing_group_id without verifying that the user was authorized to use the referenced Sharing Group.\n\nIn several attribute and Galaxy Cluster creation and editing workflows, validation of the submitted Sharing Group was performed only when the request explicitly set the distribution field to 4 (\"Sharing Group\"). An attacker could therefore craft a request containing a sharing_group_id while omitting the distribution parameter, or otherwise avoiding the distribution == 4 condition, causing the Sharing Group authorization check to be skipped.\n\nThis could allow a user with permission to create or modify the affected MISP objects to associate data with a Sharing Group that they are not authorized to use. Depending on the affected object\u0027s existing distribution settings and subsequent processing, this could bypass intended information-sharing boundaries and result in unauthorized placement or distribution of data to members of another Sharing Group.\n\nThe issue affected attribute attachment and editing operations as well as Galaxy Cluster creation and editing. The fix ensures that authorization is performed whenever a non-empty sharing_group_id is submitted, independently of the distribution parameter. It also centralizes the authorization decision in SharingGroup::canUse() and explicitly rejects empty Sharing Group identifiers rather than allowing them to be interpreted as an unrestricted query."
        }
      ],
      "impacts": [
        {
          "capecId": "CAPEC-1",
          "descriptions": [
            {
              "lang": "en",
              "value": "CAPEC-1 Accessing Functionality Not Properly Constrained by ACLs"
            }
          ]
        }
      ],
      "metrics": [
        {
          "cvssV4_0": {
            "Automatable": "NOT_DEFINED",
            "Recovery": "NOT_DEFINED",
            "Safety": "NOT_DEFINED",
            "attackComplexity": "LOW",
            "attackRequirements": "PRESENT",
            "attackVector": "NETWORK",
            "baseScore": 7.6,
            "baseSeverity": "HIGH",
            "privilegesRequired": "LOW",
            "providerUrgency": "NOT_DEFINED",
            "subAvailabilityImpact": "NONE",
            "subConfidentialityImpact": "NONE",
            "subIntegrityImpact": "NONE",
            "userInteraction": "NONE",
            "valueDensity": "NOT_DEFINED",
            "vectorString": "CVSS:4.0/AV:N/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:N/SC:N/SI:N/SA:N",
            "version": "4.0",
            "vulnAvailabilityImpact": "NONE",
            "vulnConfidentialityImpact": "HIGH",
            "vulnIntegrityImpact": "HIGH",
            "vulnerabilityResponseEffort": "NOT_DEFINED"
          },
          "format": "CVSS",
          "scenarios": [
            {
              "lang": "en",
              "value": "GENERAL"
            }
          ]
        }
      ],
      "problemTypes": [
        {
          "descriptions": [
            {
              "cweId": "CWE-862",
              "description": "CWE-862 Missing Authorization",
              "lang": "en",
              "type": "CWE"
            }
          ]
        }
      ],
      "providerMetadata": {
        "dateUpdated": "2026-09-04T08:53:46.725Z",
        "orgId": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
        "shortName": "CIRCL"
      },
      "references": [
        {
          "tags": [
            "patch"
          ],
          "url": "https://github.com/MISP/MISP/commit/9b1363955"
        }
      ],
      "source": {
        "discovery": "UNKNOWN"
      },
      "title": "MISP Sharing Group Authorization Bypass via Omitted Distribution Parameter",
      "x_generator": {
        "engine": "Vulnogram 0.2.0"
      }
    }
  },
  "cveMetadata": {
    "assignerOrgId": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
    "assignerShortName": "CIRCL",
    "cveId": "CVE-2026-85533",
    "datePublished": "2026-09-04T08:53:46.725Z",
    "dateReserved": "2026-09-04T08:53:39.237Z",
    "dateUpdated": "2026-09-04T08:53:46.725Z",
    "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.

Detection rules are retrieved from Rulezet.

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.

Action not permitted

GHSA-4PV3-XJC8-WFM8

CVE-2026-85533 (GCVE-0-2026-85533)

Tags

Sightings

Nomenclature