{"id":"CVE-2026-48982","summary":"pam_usb: Missing O_EXCL on pad temp file creation allows concurrent update race","details":"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.","aliases":["GHSA-hxh6-9574-5vp6"],"modified":"2026-10-28T11:11:27.846749931Z","published":"2026-06-18T19:01:08.766Z","database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48982.json","cna_assigner":"GitHub_M","cwe_ids":["CWE-362"]},"references":[{"type":"WEB","url":"https://github.com/mcdope/pam_usb/releases/tag/0.9.2"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/48xxx/CVE-2026-48982.json"},{"type":"ADVISORY","url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-hxh6-9574-5vp6"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-48982"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://github.com/mcdope/pam_usb","events":[{"introduced":"0"},{"fixed":"d4083e266b7e18e41e58b3392b5856941a3b5b1c"}],"database_specific":{"extracted_events":[{"range":[{"introduced":"0"},{"fixed":"0.9.2"}],"source":"AFFECTED_FIELD","strategy":"StringRangeExpression"},{"original_tag":"0.9.2","range":[{"fixed":"d4083e266b7e18e41e58b3392b5856941a3b5b1c"}],"source":"REFERENCES_TAG"},{"source":"DESCRIPTION","range":[{"introduced":"0"},{"fixed":"0.9.2"}]}]}}],"versions":["0.9.1","0.9.0","0.8.7","0.8.4","0.8.3","v0.8.0","0.7.3","0.7.2","0.7.1","v0.7.0","0.5.0"],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-48982.json","vanir_signatures":[{"signature_version":"v1","source":"https://github.com/mcdope/pam_usb/commit/d4083e266b7e18e41e58b3392b5856941a3b5b1c","target":{"file":"src/version.h"},"deprecated":false,"digest":{"threshold":0.9,"line_hashes":["207168628483260584139415185282640304588"]},"id":"CVE-2026-48982-efc14bc2","signature_type":"Line"}],"vanir_signatures_modified":"2026-10-28T11:11:27Z"}}],"schema_version":"1.9.2","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:L/I:H/A:L"}]}