pam_usb: TOCTOU race condition in pad directory creation allows symlink substitution_CVE-2026-48983

{
    "lastseen": "",
    "description": "pam_usb provides hardware authentication for Linux using ordinary removable media. In versions prior to 0.9.2, a symlink race condition exists in per-device and per-user pad directory creation. pam_usb uses a check-then-act pattern: it calls lstat() to test for existence and then calls mkdir() separately to create the directory. A local attacker can win the race between these calls by replacing the target path with a symlink to a directory they control. If successful, one-time pad files may be written to an attacker-controlled location, potentially exposing future pad values before use or disrupting authentication. This issue has been fixed in version 0.9.2.",
    "published": "2026-06-18T19:07:56.198Z",
    "modified": "2026-06-18T19:07:56.198Z",
    "type": "cve",
    "title": "pam_usb: TOCTOU race condition in pad directory creation allows symlink substitution",
    "source": "GitHub_M",
    "references": "https://github.com/mcdope/pam_usb/security/advisories/GHSA-4j8q-67fq-3xc3\nhttps://github.com/mcdope/pam_usb/releases/tag/0.9.2",
    "id": "CVE-2026-48983",
    "bulletinFamily": "",
    "cwe": [
        "CWE-367"
    ],
    "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:H/I:L/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
}