{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-27590",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-02-20T17:40:28.450Z",
        "datePublished": "2026-02-24T16:33:41.353Z",
        "dateUpdated": "2026-02-27T20:52:00.327Z"
    },
    "containers": {
        "cna": {
            "title": "Caddy: Unicode case-folding length expansion causes incorrect split_path index (SCRIPT_NAME/PATH_INFO confusion) in FastCGI transport",
            "problemTypes": [
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-20",
                            "lang": "en",
                            "description": "CWE-20: Improper Input Validation",
                            "type": "CWE"
                        }
                    ]
                },
                {
                    "descriptions": [
                        {
                            "cweId": "CWE-180",
                            "lang": "en",
                            "description": "CWE-180: Incorrect Behavior Order: Validate Before Canonicalize",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV4_0": {
                        "attackVector": "NETWORK",
                        "attackComplexity": "LOW",
                        "attackRequirements": "NONE",
                        "privilegesRequired": "NONE",
                        "userInteraction": "NONE",
                        "vulnConfidentialityImpact": "HIGH",
                        "vulnIntegrityImpact": "HIGH",
                        "vulnAvailabilityImpact": "HIGH",
                        "subConfidentialityImpact": "NONE",
                        "subIntegrityImpact": "NONE",
                        "subAvailabilityImpact": "NONE",
                        "baseScore": 8.9,
                        "baseSeverity": "HIGH",
                        "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:P",
                        "version": "4.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/caddyserver/caddy/security/advisories/GHSA-5r3v-vc8m-m96g",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/caddyserver/caddy/security/advisories/GHSA-5r3v-vc8m-m96g"
                },
                {
                    "name": "https://github.com/php/frankenphp/security/advisories/GHSA-g966-83w7-6w38",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/php/frankenphp/security/advisories/GHSA-g966-83w7-6w38"
                },
                {
                    "name": "https://github.com/caddyserver/caddy/releases/tag/v2.11.1",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/caddyserver/caddy/releases/tag/v2.11.1"
                }
            ],
            "affected": [
                {
                    "vendor": "caddyserver",
                    "product": "caddy",
                    "versions": [
                        {
                            "version": "< 2.11.1",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-02-24T16:33:41.353Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Caddy is an extensible server platform that uses TLS by default. Prior to version 2.11.1, Caddy's FastCGI path splitting logic computes the split index on a lowercased copy of the request path and then uses that byte index to slice the original path. This is unsafe for Unicode because `strings.ToLower()` can change UTF-8 byte length for some characters. As a result, Caddy can derive an incorrect `SCRIPT_NAME`/`SCRIPT_FILENAME` and `PATH_INFO`, potentially causing a request that contains `.php` to execute a different on-disk file than intended (path confusion). In setups where an attacker can control file contents (e.g., upload features), this can lead to unintended PHP execution of non-.php files (potential RCE depending on deployment). Version 2.11.1 fixes the issue."
                }
            ],
            "source": {
                "advisory": "GHSA-5r3v-vc8m-m96g",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-02-27T20:51:50.628047Z",
                                "id": "CVE-2026-27590",
                                "options": [
                                    {
                                        "Exploitation": "poc"
                                    },
                                    {
                                        "Automatable": "yes"
                                    },
                                    {
                                        "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": "2026-02-27T20:52:00.327Z"
                }
            }
        ]
    }
}