pam_usb: Missing O_EXCL on pad temp file creation allows concurrent update race_CVE-2026-48982

{
    "lastseen": "",
    "description": "pam_usb provides hardware authentication for Linux using ordinary removable media. In versions prior to 0.9.2, when updating a one-time pad file, a temporary file is created using open() without the O_EXCL flag. Without O_EXCL, the create operation is not atomic: two concurrent processes racing to update the same pad may both succeed in opening the file, with the second write silently overwriting the first. The one-time pad is the core replay-prevention mechanism of pam_usb. A successful race could result in the stored pad value diverging from what either process expected, potentially causing authentication failures or, in a precisely timed attack, creating a window for pad reuse. This issue has been fixed in version 0.9.2.",
    "published": "2026-06-18T19:01:08.766Z",
    "modified": "2026-06-18T19:01:08.766Z",
    "type": "cve",
    "title": "pam_usb: Missing O_EXCL on pad temp file creation allows concurrent update race",
    "source": "GitHub_M",
    "references": "https://github.com/mcdope/pam_usb/security/advisories/GHSA-hxh6-9574-5vp6\nhttps://github.com/mcdope/pam_usb/releases/tag/0.9.2",
    "id": "CVE-2026-48982",
    "bulletinFamily": "",
    "cwe": [
        "CWE-362"
    ],
    "cvelist": null,
    "sourceData": "mcdope pam_usb < 0.9.2",
    "sourceHref": "",
    "cvss": {
        "score": 5.8,
        "severity": "MEDIUM",
        "vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L",
        "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": "pam_usb",
    "version": "< 0.9.2",
    "vendor": "mcdope",
    "ai_description": "",
    "ai_severity": "",
    "ai_vendor": "",
    "ai_product": "",
    "ai_version": "",
    "ai_score": 0
}