morgan vulnerable to Log Forging via unneutralized control characters in :remote-user_CVE-2026-5078

{
    "lastseen": "",
    "description": "Impact: The morgan logging middleware's :remote-user token extracts the Basic auth username from the Authorization request header and writes it to the log stream without neutralizing control characters. An unauthenticated attacker can send a crafted Authorization Basic header containing CR or LF bytes to inject forged log lines, breaking the one-request-per-line structure of access logs and enabling log forgery against downstream log consumers. The built-in combined, common, default, and short formats are affected, as well as any custom format that references :remote-user. Affected versions: morgan 1.2.0 through 1.10.1. Patches: upgrade to morgan 1.11.0, which neutralizes control characters in the :remote-user token output. Workarounds: use a custom format string that does not include :remote-user.",
    "published": "2026-06-03T05:56:49.512Z",
    "modified": "2026-06-03T05:56:49.512Z",
    "type": "cve",
    "title": "morgan vulnerable to Log Forging via unneutralized control characters in :remote-user",
    "source": "openjs",
    "references": "https://github.com/expressjs/morgan/security/advisories/GHSA-4vj7-5mj6-jm8m\nhttps://cna.openjsf.org/security-advisories.html",
    "id": "CVE-2026-5078",
    "bulletinFamily": "",
    "cwe": [
        "CWE-117"
    ],
    "cvelist": null,
    "sourceData": "morgan morgan 1.2.0",
    "sourceHref": "",
    "cvss": {
        "score": 5.3,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N",
        "version": "3.1"
    },
    "cvss2": [],
    "cvss3": {
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        "baseScore": 0,
        "baseSeverity": "",
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        "attackComplexity": "",
        "privilegesRequired": "",
        "userInteraction": "",
        "scope": "",
        "confidentialityImpact": "",
        "integrityImpact": "",
        "availabilityImpact": "",
        "cvssV3": {
            "version": "",
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            "baseScore": 0,
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        }
    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "morgan",
    "version": "1.2.0",
    "vendor": "morgan",
    "ai_description": "",
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    "ai_score": 0
}