Roundcube Local/Private URL Fetch Bypass_CVE-2026-9818

4.7 / 10

MEDIUM

CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/I:L/A:N

Description

Roundcube's HTML sanitization path for message rendering allows loopback, localhost, RFC1918, link-local, and ULA URLs even when remote content loading is disabled. A remote attacker can send an HTML email that causes the victim's browser to issue requests to local or private-network services simply by opening the message preview.

Basic Information

ID CVE-2026-9818

Source OCD

Published May 28, 2026 at 12:16

Affected Product

Vendor Roundcube

Product Webmail

Affected Versions Roundcube Webmail 0
Roundcube Webmail 1.7.0

CWE Classification

CWE-184

References

{
    "lastseen": "",
    "description": "Roundcube's HTML sanitization path for message rendering allows loopback, localhost, RFC1918, link-local, and ULA URLs even when remote content loading is disabled. A remote attacker can send an HTML email that causes the victim's browser to issue requests to local or private-network services simply by opening the message preview.",
    "published": "2026-05-28T12:16:05.464Z",
    "modified": "2026-05-28T12:16:05.464Z",
    "type": "cve",
    "title": "Roundcube Local/Private URL Fetch Bypass",
    "source": "OCD",
    "references": "https://github.com/roundcube/roundcubemail/releases/tag/1.7.1\nhttps://github.com/roundcube/roundcubemail/releases/tag/1.6.16\nhttps://github.com/roundcube/roundcubemail/commit/faf867432f51ebbe100382a70a9e3c042415ee1b\nhttps://github.com/roundcube/roundcubemail/commit/7b52353653a67e6073b97d70eb94047132b78556\nhttps://advisories.orangecyberdefense.com/advisories/163",
    "id": "CVE-2026-9818",
    "bulletinFamily": "",
    "cwe": [
        "CWE-184"
    ],
    "cvelist": null,
    "sourceData": "Roundcube Webmail 0\nRoundcube Webmail 1.7.0",
    "sourceHref": "",
    "cvss": {
        "score": 4.7,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:N/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": "Webmail",
    "version": "0",
    "vendor": "Roundcube",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}