Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libxfont2 name length mismatch_CVE-2026-50256

{
    "lastseen": "",
    "description": "A stack-based buffer overflow flaw was found in the X.Org X server and Xwayland. A mismatch between the X server and the libXfont2 library's maximum font name length can cause a stack buffer overflow during font alias resolution. The server allocates a 256 byte stack buffer but libXfont2's alias target name length is 1024 bytes. A font alias name between 257 and 1023 bytes causes the X server to copy that name into the undersized stack buffer without further checks. This may be used to crash the server, or for privilege escalation if the X server runs as root.",
    "published": "2026-06-05T10:31:22.122Z",
    "modified": "2026-06-05T10:31:22.122Z",
    "type": "cve",
    "title": "Xorg-x11-server: xorg-x11-server-xwayland: xorg-x11-server: stack buffer overflow in font alias resolution due to libxfont2 name length mismatch",
    "source": "redhat",
    "references": "https://access.redhat.com/security/cve/CVE-2026-50256\nhttps://bugzilla.redhat.com/show_bug.cgi?id=2485380\nhttps://gitlab.freedesktop.org/xorg/xserver/-/commit/bb5158f962dc935e58ef8b4b5fcb31be201a6e07\nhttps://lists.x.org/archives/xorg-announce/2026-June/003702.html\nhttps://redhat.atlassian.net/browse/PSIRTSUPT-16950",
    "id": "CVE-2026-50256",
    "bulletinFamily": "",
    "cwe": [
        "CWE-121"
    ],
    "cvelist": null,
    "sourceData": "",
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    "cvss": {
        "score": 7.8,
        "severity": "HIGH",
        "vector": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H",
        "version": "3.1"
    },
    "cvss2": [],
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        "baseScore": 0,
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        "privilegesRequired": "",
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        "confidentialityImpact": "",
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        "availabilityImpact": "",
        "cvssV3": {
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    },
    "href": "",
    "category_name": "CVE",
    "post_link": "",
    "product": "Red Hat Enterprise Linux 10",
    "version": "",
    "vendor": "Red Hat",
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    "ai_score": 0
}