{"id":"CVE-2026-48982","aliases":["EUVD-2026-37935","GHSA-hxh6-9574-5vp6"],"status":"published","title":"pam_usb: Missing O_EXCL on pad temp file creation allows concurrent update race","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.","severity":{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.00118,"percentile":0.01714,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-362"],"published":"2026-06-18T19:01:08Z","modified":"2026-10-28T11:11:27Z","products":[{"vendor":"mcdope","product":"pam_usb"}],"references":[{"url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-hxh6-9574-5vp6","tags":["x_refsource_CONFIRM","advisory"]},{"url":"https://github.com/mcdope/pam_usb/releases/tag/0.9.2","tags":["x_refsource_MISC","web"]},{"url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48982.json","tags":["advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48982","tags":["advisory"]}],"sources":{"cve":[{"id":"CVE-2026-48982","title":"pam_usb: Missing O_EXCL on pad temp file creation allows concurrent update race","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.","status":"published","published":"2026-06-18T19:01:08.766Z","modified":"2026-06-22T17:16:39.634Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium","assessor":"cna"}],"cwes":["CWE-362"],"updated_at":"2026-11-02T14:19:47.998488Z"}],"euvd":[{"id":"EUVD-2026-37935","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.","status":"published","published":"2026-06-18T19:01:08Z","modified":"2026-06-22T17:16:39Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium"}],"updated_at":"2026-11-02T18:20:34.238696Z"}],"nvd":[{"id":"CVE-2026-48982","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.","status":"published","published":"2026-06-18T20:16:14.53Z","modified":"2026-10-26T11:10:00.157Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium","assessor":"secondary"}],"cwes":["CWE-362"],"updated_at":"2026-11-02T14:12:24.912854Z"}],"osv":[{"id":"CVE-2026-48982","title":"pam_usb: Missing O_EXCL on pad temp file creation allows concurrent update race","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.","status":"published","published":"2026-06-18T19:01:08.766Z","modified":"2026-10-28T11:11:27.846749931Z","cvss":[{"version":"3.1","score":5.8,"vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L","level":"medium"}],"cwes":["CWE-362"],"updated_at":"2026-11-02T15:45:07.060148Z"}]}}