{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-85238",
        "assignerOrgId": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
        "state": "PUBLISHED",
        "assignerShortName": "CIRCL",
        "dateReserved": "2026-09-03T15:29:58.290Z",
        "datePublished": "2026-09-03T15:30:42.478Z",
        "dateUpdated": "2026-09-03T15:43:12.832Z"
    },
    "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": "Scottish Government - National Cyber Team"
                },
                {
                    "lang": "en",
                    "type": "finder",
                    "value": "Peter James"
                }
            ],
            "descriptions": [
                {
                    "lang": "en",
                    "supportingMedia": [
                        {
                            "base64": false,
                            "type": "text/html",
                            "value": "<p>MISP contains a session fixation vulnerability in the <strong>CustomAuth authentication (a custom configuration) flow</strong>. When a user was successfully authenticated through CustomAuth, MISP stored the authenticated user identity in the existing session without first rotating the session identifier.</p>\n<p>As a result, if an attacker can cause a victim to use a session identifier known to the attacker before authentication, that same session identifier remains valid after the victim successfully authenticates. The attacker could subsequently reuse the fixed session identifier to access the victim's authenticated MISP session, potentially gaining the privileges associated with the victim's account.</p>\n<p>The issue occurs because <code>__customAuthentication()</code> wrote the authenticated user into the existing CakePHP session while the call to <code>Session-&gt;renew()</code> had previously been disabled. The patch restores session identifier rotation when a <strong>new authentication</strong> occurs or when the authenticated user changes, while avoiding unnecessary session renewal on every request.</p><br>"
                        }
                    ],
                    "value": "MISP contains a session fixation vulnerability in the CustomAuth authentication (a custom configuration) flow. When a user was successfully authenticated through CustomAuth, MISP stored the authenticated user identity in the existing session without first rotating the session identifier.\n\n\nAs a result, if an attacker can cause a victim to use a session identifier known to the attacker before authentication, that same session identifier remains valid after the victim successfully authenticates. The attacker could subsequently reuse the fixed session identifier to access the victim's authenticated MISP session, potentially gaining the privileges associated with the victim's account.\n\n\nThe issue occurs because __customAuthentication() wrote the authenticated user into the existing CakePHP session while the call to Session->renew() had previously been disabled. The patch restores session identifier rotation when a new authentication occurs or when the authenticated user changes, while avoiding unnecessary session renewal on every request."
                }
            ],
            "impacts": [
                {
                    "capecId": "CAPEC-61",
                    "descriptions": [
                        {
                            "lang": "en",
                            "value": "CAPEC-61 Session Fixation"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "Automatable": "NOT_DEFINED",
                        "Recovery": "NOT_DEFINED",
                        "Safety": "NOT_DEFINED",
                        "attackComplexity": "HIGH",
                        "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:H/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-384",
                            "description": "CWE-384 Session Fixation",
                            "lang": "en",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "5a6e4751-2f3f-4070-9419-94fb35b644e8",
                "shortName": "CIRCL",
                "dateUpdated": "2026-09-03T15:30:42.478Z"
            },
            "references": [
                {
                    "tags": [
                        "patch"
                    ],
                    "url": "https://github.com/MISP/MISP/commit/e2eb2f058"
                }
            ],
            "source": {
                "discovery": "UNKNOWN"
            },
            "title": "Session Fixation in MISP CustomAuth Authentication Allows Session Hijacking",
            "x_generator": {
                "engine": "Vulnogram 0.2.0"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-03T15:43:07.468576Z",
                                "id": "CVE-2026-85238",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-09-03T15:43:12.832Z"
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    }
}