{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-71478",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-08-06T19:56:23.724Z",
        "datePublished": "2026-08-06T20:30:32.045Z",
        "dateUpdated": "2026-08-07T17:05:57.244Z"
    },
    "containers": {
        "cna": {
            "title": "league/commonmark: AttributesExtension href/src unsafe-link filter bypass via embedded control bytes",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-79",
                            "lang": "en",
                            "description": "CWE-79: Improper Neutralization of Input During Web Page Generation ('Cross-site Scripting')",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-86",
                            "lang": "en",
                            "description": "CWE-86: Improper Neutralization of Invalid Characters in Identifiers in Web Pages",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-692",
                            "lang": "en",
                            "description": "CWE-692: Incomplete Denylist to Cross-Site Scripting",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_1": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 6.1,
                        "baseSeverity": "MEDIUM",
                        "confidentialityImpact": "LOW",
                        "integrityImpact": "LOW",
                        "privilegesRequired": "NONE",
                        "scope": "CHANGED",
                        "userInteraction": "REQUIRED",
                        "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N",
                        "version": "3.1"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-29pj-957v-52mc",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-29pj-957v-52mc"
                },
                {
                    "name": "https://github.com/thephpleague/commonmark/commit/493a5aa7d65754b73846006eaff9c2c4431a8e2c",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/thephpleague/commonmark/commit/493a5aa7d65754b73846006eaff9c2c4431a8e2c"
                },
                {
                    "name": "https://github.com/thephpleague/commonmark/releases/tag/2.9.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/thephpleague/commonmark/releases/tag/2.9.0"
                }
            ],
            "affected": [
                {
                    "vendor": "thephpleague",
                    "product": "commonmark",
                    "versions": [
                        {
                            "version": ">= 1.5.0, <= 2.8.3",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-08-06T20:30:32.045Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "league/commonmark is a PHP library for parsing and rendering CommonMark Markdown. From 1.5.0 until 2.9.0, the AttributesExtension's href and src unsafe-link filter can be bypassed by embedding control bytes, such as a tab, carriage return, line feed, or leading C0 control character, in a javascript: URL that browsers discard before parsing the scheme, causing the browser to still execute the script even when the unsafe-link filter is enabled. This issue is fixed in 2.9.0."
                }
            ],
            "source": {
                "advisory": "GHSA-29pj-957v-52mc",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/thephpleague/commonmark/security/advisories/GHSA-29pj-957v-52mc",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-08-07T17:04:55.894840Z",
                                "id": "CVE-2026-71478",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "no"
                                    },
                                    {
                                        "Technical Impact": "partial"
                                    }
                                ],
                                "role": "CISA Coordinator",
                                "version": "2.0.3"
                            }
                        }
                    }
                ],
                "title": "CISA ADP Vulnrichment",
                "providerMetadata": {
                    "orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0",
                    "shortName": "CISA-ADP",
                    "dateUpdated": "2026-08-07T17:05:57.244Z"
                }
            }
        ]
    }
}