{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-23986",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-01-19T18:49:20.656Z",
        "datePublished": "2026-01-21T22:20:37.720Z",
        "dateUpdated": "2026-01-22T16:49:26.426Z"
    },
    "containers": {
        "cna": {
            "title": "Copier safe template has arbitrary filesystem write access via directory symlinks when _preserve_symlinks: true",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-61",
                            "lang": "en",
                            "description": "CWE-61: UNIX Symbolic Link (Symlink) Following",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "LOCAL",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "PASSIVE",
                        "vulnConfidentialityImpact": "NONE",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "HIGH",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 6.9,
                        "baseSeverity": "MEDIUM",
                        "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:P/VC:N/VI:H/VA:H/SC:N/SI:N/SA:N",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/copier-org/copier/security/advisories/GHSA-4fqp-r85r-hxqh",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/copier-org/copier/security/advisories/GHSA-4fqp-r85r-hxqh"
                },
                {
                    "name": "https://github.com/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/copier-org/copier/commit/b3a7b3772d17cf0e7a4481978188c9f536c8d8f6"
                },
                {
                    "name": "https://github.com/copier-org/copier/releases/tag/v9.11.2",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/copier-org/copier/releases/tag/v9.11.2"
                }
            ],
            "affected": [
                {
                    "vendor": "copier-org",
                    "product": "copier",
                    "versions": [
                        {
                            "version": "< 9.11.2",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-01-21T22:20:37.720Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Copier is a library and CLI app for rendering project templates. Prior to version 9.11.2, Copier suggests that it's safe to generate a project from a safe template, i.e. one that doesn't use unsafe features like custom Jinja extensions which would require passing the `--UNSAFE,--trust` flag. As it turns out, a safe template can currently write to arbitrary directories outside the destination path by using directory a symlink along with `_preserve_symlinks: true` and a generated directory structure whose rendered path is inside the symlinked directory. This way, a malicious template author can create a template that overwrites arbitrary files (according to the user's write permissions), e.g., to cause havoc. Version 9.11.2 patches the issue."
                }
            ],
            "source": {
                "advisory": "GHSA-4fqp-r85r-hxqh",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-01-22T15:10:50.987653Z",
                                "id": "CVE-2026-23986",
                                "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": "2026-01-22T16:49:26.426Z"
                }
            }
        ]
    }
}