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CVE-2026-103388

Status: DeferredMedium (6.2)—

MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.

When another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.

Preconditions:

- Attacker must hold galaxy editor privileges (local or via sync).

Read full descriptionShow less

- Victim must view the affected cluster and click the malicious link.

Impact:

- Stored cross-site scripting (XSS) in the victim's browser.

- Potential session theft, credential harvesting, or unauthorized actions within the MISP application.

Affected: <2.5.48.

CVSS

Exploitation probability (EPSS)

EPSS (Exploit Prediction Scoring System, FIRST) estimates how likely a vulnerability is to be exploited in the wild within 30 days. It complements CVSS (impact) and CISA KEV (confirmed exploitation).

Affected technologies (1)

⚠ AI-inferred from the description — NVD hasn't analyzed this CVE yet, these aren't verified CPEs.

Misp — MispAI

CWEs

References

Raw JSON (NVD)

Show
{
  "id": "CVE-2026-103388",
  "cveTags": [],
  "metrics": {
    "ssvcV203": [
      {
        "source": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
        "ssvcData": {
          "id": "CVE-2026-103388",
          "role": "CISA Coordinator",
          "options": [
            {
              "exploitation": "none"
            },
            {
              "automatable": "no"
            },
            {
              "technicalImpact": "partial"
            }
          ],
          "version": "2.0.3",
          "timestamp": "2026-09-30T14:58:39.451751Z"
        }
      }
    ],
    "cvssMetricV40": [
      {
        "type": "Secondary",
        "source": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
        "cvssData": {
          "Safety": "NOT_DEFINED",
          "version": "4.0",
          "Recovery": "NOT_DEFINED",
          "baseScore": 6.2,
          "Automatable": "NOT_DEFINED",
          "attackVector": "NETWORK",
          "baseSeverity": "MEDIUM",
          "valueDensity": "NOT_DEFINED",
          "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:A/VC:N/VI:N/VA:N/SC:H/SI:H/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",
          "exploitMaturity": "NOT_DEFINED",
          "providerUrgency": "NOT_DEFINED",
          "userInteraction": "ACTIVE",
          "attackComplexity": "LOW",
          "attackRequirements": "NONE",
          "privilegesRequired": "LOW",
          "subIntegrityImpact": "HIGH",
          "vulnIntegrityImpact": "NONE",
          "integrityRequirement": "NOT_DEFINED",
          "modifiedAttackVector": "NOT_DEFINED",
          "subAvailabilityImpact": "NONE",
          "vulnAvailabilityImpact": "NONE",
          "availabilityRequirement": "NOT_DEFINED",
          "modifiedUserInteraction": "NOT_DEFINED",
          "modifiedAttackComplexity": "NOT_DEFINED",
          "subConfidentialityImpact": "HIGH",
          "vulnConfidentialityImpact": "NONE",
          "confidentialityRequirement": "NOT_DEFINED",
          "modifiedAttackRequirements": "NOT_DEFINED",
          "modifiedPrivilegesRequired": "NOT_DEFINED",
          "modifiedSubIntegrityImpact": "NOT_DEFINED",
          "modifiedVulnIntegrityImpact": "NOT_DEFINED",
          "vulnerabilityResponseEffort": "NOT_DEFINED",
          "modifiedSubAvailabilityImpact": "NOT_DEFINED",
          "modifiedVulnAvailabilityImpact": "NOT_DEFINED",
          "modifiedSubConfidentialityImpact": "NOT_DEFINED",
          "modifiedVulnConfidentialityImpact": "NOT_DEFINED"
        }
      }
    ]
  },
  "affected": [
    {
      "source": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
      "affectedData": [
        {
          "cpes": [
            "cpe:2.3:a:misp:misp:*:*:*:*:*:*:*:*"
          ],
          "repo": "https://github.com/MISP/MISP",
          "vendor": "MISP",
          "modules": [
            "GalaxyClusters view (default theme)",
            "GalaxyClusters view (Overmind theme)"
          ],
          "product": "MISP",
          "versions": [
            {
              "status": "affected",
              "version": "0",
              "lessThan": "2.5.48",
              "versionType": "semver"
            }
          ],
          "programFiles": [
            "app/View/GalaxyClusters/view.ctp",
            "app/View/Themed/Overmind/Elements/GalaxyClusters/View/galaxy_clusters_general.ctp"
          ]
        }
      ]
    }
  ],
  "published": "2026-09-30T15:22:27.143",
  "references": [
    {
      "url": "https://github.com/MISP/MISP/commit/118528767",
      "source": "5a6e4751-2f3f-4070-9419-94fb35b644e8"
    }
  ],
  "vulnStatus": "Deferred",
  "weaknesses": [
    {
      "type": "Secondary",
      "source": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
      "description": [
        {
          "lang": "en",
          "value": "CWE-79"
        }
      ]
    }
  ],
  "descriptions": [
    {
      "lang": "en",
      "value": "MISP renders the source field of a Galaxy Cluster as a clickable hyperlink whenever the stored value passes PHP's FILTER_VALIDATE_URL validation. Because FILTER_VALIDATE_URL accepts the javascript: URI scheme, a user with galaxy editor privileges on the local instance or on a synced instance could store a javascript: URL as the cluster source.\n\nWhen another user views the affected Galaxy Cluster and clicks the rendered link, the embedded script executes in the victim's browser context, enabling session hijacking, data exfiltration, or actions performed on behalf of the victim.\n\nPreconditions:\n\n- Attacker must hold galaxy editor privileges (local or via sync).\n\n- Victim must view the affected cluster and click the malicious link.\n\nImpact:\n\n- Stored cross-site scripting (XSS) in the victim's browser.\n\n- Potential session theft, credential harvesting, or unauthorized actions within the MISP application.\n\nAffected: <2.5.48."
    }
  ],
  "lastModified": "2026-09-30T16:17:08.983",
  "sourceIdentifier": "5a6e4751-2f3f-4070-9419-94fb35b644e8"
}