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        "cveId": "CVE-2026-12985",
        "assignerOrgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
        "state": "PUBLISHED",
        "assignerShortName": "Mattermost",
        "dateReserved": "2026-06-23T11:43:37.353Z",
        "datePublished": "2026-09-14T14:09:53.799Z",
        "dateUpdated": "2026-09-15T03:56:02.615Z"
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                    "defaultStatus": "unaffected",
                    "product": "Mattermost",
                    "vendor": "Mattermost",
                    "versions": [
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                            "lessThanOrEqual": "11.9.0",
                            "status": "affected",
                            "version": "11.9.0",
                            "versionType": "semver"
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                        {
                            "lessThanOrEqual": "11.8.4",
                            "status": "affected",
                            "version": "11.8.0",
                            "versionType": "semver"
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                            "lessThanOrEqual": "11.7.7",
                            "status": "affected",
                            "version": "11.7.0",
                            "versionType": "semver"
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                        {
                            "version": "11.10.0",
                            "status": "unaffected"
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                        {
                            "version": "11.9.1",
                            "status": "unaffected"
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                            "version": "11.8.5",
                            "status": "unaffected"
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                            "version": "11.7.8",
                            "status": "unaffected"
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                    "lang": "en",
                    "type": "finder",
                    "value": "aryangurjarf401a3"
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            ],
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Mattermost versions 11.9.x <= 11.9.0, 11.8.x <= 11.8.4, 11.7.x <= 11.7.7 Mattermost failed to validate Dynamic Client Registration redirect URIs by URL component (matching glob patterns against the raw URI string instead) which allows a remote unauthenticated attacker to register an OAuth client with an attacker-controlled callback host that bypasses the configured redirect URI allowlist via a crafted redirect URI that places an allowlisted host/path suffix inside the query string.. Mattermost Advisory ID: MMSA-2026-00700"
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "HIGH",
                        "privilegesRequired": "NONE",
                        "userInteraction": "REQUIRED",
                        "scope": "UNCHANGED",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "HIGH",
                        "availabilityImpact": "NONE",
                        "version": "3.1",
                        "vectorString": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:H/I:H/A:N",
                        "baseSeverity": "MEDIUM",
                        "baseScore": 6.8
                    },
                    "format": "CVSS",
                    "scenarios": [
                        {
                            "lang": "en",
                            "value": "GENERAL"
                        }
                    ]
                }
            ],
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "lang": "en",
                            "type": "CWE",
                            "description": "CWE-601: URL Redirection to Untrusted Site (“Open Redirect”)",
                            "cweId": "CWE-601"
                        }
                    ]
                }
            ],
            "references": [
                {
                    "url": "https://mattermost.com/security-updates",
                    "name": "MMSA-2026-00700",
                    "tags": [
                        "vendor-advisory"
                    ]
                }
            ],
            "solutions": [
                {
                    "value": "Update Mattermost to versions 11.10.0, 11.9.1, 11.8.5, 11.7.8 or higher.",
                    "lang": "en"
                }
            ],
            "source": {
                "advisory": "MMSA-2026-00700",
                "defect": [
                    "https://mattermost.atlassian.net/browse/MM-69360"
                ],
                "discovery": "EXTERNAL"
            },
            "title": "Mattermost DCR redirect URI allowlist bypass via improper URL component validation",
            "providerMetadata": {
                "orgId": "9302f53e-dde5-4bf3-b2f2-a83f91ac0eee",
                "shortName": "Mattermost",
                "dateUpdated": "2026-09-14T14:09:53.799Z"
            },
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        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-09-14T00:00:00+00:00",
                                "options": [
                                    {
                                        "Exploitation": "none"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "total"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3",
                                "id": "CVE-2026-12985"
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                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-09-15T03:56:02.615Z"
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