{"id":"CVE-2026-48983","state":"PUBLISHED","title":"pam_usb: TOCTOU race condition in pad directory creation allows symlink substitution","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.","publishedAt":"2026-06-18T19:07:56.198Z","updatedAt":"2026-06-22T12:41:34.711Z","severity":{"score":5.8,"label":"Medium","version":"3.1","vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L","source":"GitHub_M"},"assigner":"GitHub_M","products":["mcdope pam_usb"],"affected":[{"vendor":"mcdope","product":"pam_usb","versions":[{"version":"< 0.9.2","status":"affected"}]}],"references":["https://github.com/mcdope/pam_usb/security/advisories/GHSA-4j8q-67fq-3xc3","https://github.com/mcdope/pam_usb/releases/tag/0.9.2"],"weaknesses":["CWE-367"],"ingestedAt":"2026-10-29T20:12:07.131Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/48xxx/CVE-2026-48983.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-48983","state":"PUBLISHED","datePublished":"2026-06-18T19:07:56.198Z","dateUpdated":"2026-06-22T12:41:34.711Z","assignerShortName":"GitHub_M","assignerOrgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateReserved":"2026-05-26T23:26:07.975Z"},"containers":{"cna":{"title":"pam_usb: TOCTOU race condition in pad directory creation allows symlink substitution","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"mcdope","product":"pam_usb","versions":[{"version":"< 0.9.2","status":"affected"}]}],"references":[{"url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-4j8q-67fq-3xc3","name":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-4j8q-67fq-3xc3","tags":["x_refsource_CONFIRM"]},{"url":"https://github.com/mcdope/pam_usb/releases/tag/0.9.2","name":"https://github.com/mcdope/pam_usb/releases/tag/0.9.2","tags":["x_refsource_MISC"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"HIGH","attackVector":"LOCAL","availabilityImpact":"LOW","baseScore":5.8,"baseSeverity":"MEDIUM","confidentialityImpact":"HIGH","integrityImpact":"LOW","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:L/A:L","version":"3.1"}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-367","lang":"en","description":"CWE-367: Time-of-check Time-of-use (TOCTOU) Race Condition","type":"CWE"}]}],"providerMetadata":{"shortName":"GitHub_M","orgId":"a0819718-46f1-4df5-94e2-005712e83aaa","dateUpdated":"2026-06-18T19:07:56.198Z"},"source":{"advisory":"GHSA-4j8q-67fq-3xc3","discovery":"UNKNOWN"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2026-06-22T12:41:19.864255Z","id":"CVE-2026-48983","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-06-22T12:41:34.711Z"}}]}}}