{
    "dataType": "CVE_RECORD",
    "dataVersion": "5.2",
    "cveMetadata": {
        "cveId": "CVE-2026-48788",
        "assignerOrgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
        "state": "PUBLISHED",
        "assignerShortName": "GitHub_M",
        "dateReserved": "2026-05-22T20:18:20.365Z",
        "datePublished": "2026-06-16T22:29:38.877Z",
        "dateUpdated": "2026-06-17T13:20:11.543Z"
    },
    "containers": {
        "cna": {
            "title": "Remark42: Cross-Site Scripting (XSS) on /api/v1/img via content-type spoofing",
            "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-436",
                            "lang": "en",
                            "description": "CWE-436: Interpretation Conflict",
                            "type": "CWE"
                        }
                    ]
                }
            ],
            "metrics": [
                {
                    "cvssV3_0": {
                        "attackComplexity": "LOW",
                        "attackVector": "NETWORK",
                        "availabilityImpact": "NONE",
                        "baseScore": 8.2,
                        "baseSeverity": "HIGH",
                        "confidentialityImpact": "HIGH",
                        "integrityImpact": "LOW",
                        "privilegesRequired": "NONE",
                        "scope": "CHANGED",
                        "userInteraction": "REQUIRED",
                        "vectorString": "CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:L/A:N",
                        "version": "3.0"
                    }
                }
            ],
            "references": [
                {
                    "name": "https://github.com/umputun/remark42/security/advisories/GHSA-4c8j-mgm4-qqvp",
                    "tags": [
                        "x_refsource_CONFIRM"
                    ],
                    "url": "https://github.com/umputun/remark42/security/advisories/GHSA-4c8j-mgm4-qqvp"
                },
                {
                    "name": "https://github.com/umputun/remark42/commit/78d6de6bce1e961f023969da3ec8a00dd80c9ae8",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/umputun/remark42/commit/78d6de6bce1e961f023969da3ec8a00dd80c9ae8"
                },
                {
                    "name": "https://github.com/umputun/remark42/releases/tag/v1.16.0",
                    "tags": [
                        "x_refsource_MISC"
                    ],
                    "url": "https://github.com/umputun/remark42/releases/tag/v1.16.0"
                }
            ],
            "affected": [
                {
                    "vendor": "umputun",
                    "product": "remark42",
                    "versions": [
                        {
                            "version": ">= 1.6.0, < 1.16.0",
                            "status": "affected"
                        }
                    ]
                }
            ],
            "providerMetadata": {
                "orgId": "a0819718-46f1-4df5-94e2-005712e83aaa",
                "shortName": "GitHub_M",
                "dateUpdated": "2026-06-16T22:29:38.877Z"
            },
            "descriptions": [
                {
                    "lang": "en",
                    "value": "Remark42 is a self-hosted comment engine for blogs, articles, or any other place where readers can add comments. Versions 1.6.0 through 1.15.0 contain a Cross-Site Scripting (XSS) vulnerability exploitable through content-type spoofing. The Remark42 image proxy fetches an arbitrary remote URL and re-serves the response from Remark42's own origin. During the download phase, the proxy determines whether the resource is an image by inspecting only the Content-Type header advertised by the remote server, never examining the actual bytes; during the serving phase, it instead derives the response Content-Type by sniffing those bytes with http.DetectContentType. An attacker can exploit this inconsistency by hosting a URL that advertises Content-Type: image/png while returning an HTML/JavaScript body: the download check accepts it as an image, the serving path sniffs the body and emits Content-Type: text/html, and the browser renders the attacker-controlled HTML/JavaScript as a document within Remark42's origin. Exploitation requires no Remark42 account on the target instance; the attacker only needs to host the malicious upstream URL and deliver the proxy link to a victim by any means, such as email, direct message, or a link on another website. This issue has been fixed in version 1.16.0."
                }
            ],
            "source": {
                "advisory": "GHSA-4c8j-mgm4-qqvp",
                "discovery": "UNKNOWN"
            }
        },
        "adp": [
            {
                "references": [
                    {
                        "url": "https://github.com/umputun/remark42/security/advisories/GHSA-4c8j-mgm4-qqvp",
                        "tags": [
                            "exploit"
                        ]
                    }
                ],
                "metrics": [
                    {
                        "other": {
                            "type": "ssvc",
                            "content": {
                                "timestamp": "2026-06-17T13:19:50.596883Z",
                                "id": "CVE-2026-48788",
                                "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": "2026-06-17T13:20:11.543Z"
                }
            }
        ]
    }
}