Postiz: TOCTOU DNS rebinding bypasses all SSRF URL validation paths_CVE-2026-42346

{
    "lastseen": "",
    "description": "Postiz is an AI social media scheduling tool. From version 2.16.6 to before version 2.21.7, all SSRF protections added in v2.21.4\u2013v2.21.6 share a fundamental TOCTOU (Time-of-Check-Time-of-Use) vulnerability: isSafePublicHttpsUrl() resolves DNS to validate the target IP, but subsequent fetch() calls resolve DNS independently. An attacker controlling a DNS server can exploit this gap via DNS rebinding to redirect requests to internal network addresses. This issue has been patched in version 2.21.7.",
    "published": "2026-05-08T22:26:50.501Z",
    "modified": "2026-05-08T22:26:50.501Z",
    "type": "cve",
    "title": "Postiz: TOCTOU DNS rebinding bypasses all SSRF URL validation paths",
    "source": "GitHub_M",
    "references": "https://github.com/gitroomhq/postiz-app/security/advisories/GHSA-f7jj-p389-4w45\nhttps://github.com/gitroomhq/postiz-app/commit/071143dcb01cdeb9d5d7019892f4c6ff7b19dbeb\nhttps://github.com/gitroomhq/postiz-app/releases/tag/v2.21.7",
    "id": "CVE-2026-42346",
    "bulletinFamily": "",
    "cwe": [
        "CWE-918"
    ],
    "cvelist": null,
    "sourceData": "gitroomhq postiz-app >= 2.16.6, < 2.21.7",
    "sourceHref": "",
    "cvss": {
        "score": 6.5,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:L/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
        "version": "",
        "vectorString": "",
        "baseScore": 0,
        "baseSeverity": "",
        "attackVector": "",
        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
            "vectorString": "",
            "baseScore": 0,
            "baseSeverity": "",
            "attackVector": "",
            "attackComplexity": "",
            "privilegesRequired": "",
            "userInteraction": "",
            "scope": "",
            "confidentialityImpact": "",
            "integrityImpact": "",
            "availabilityImpact": ""
        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "postiz-app",
    "version": ">= 2.16.6, < 2.21.7",
    "vendor": "gitroomhq",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}