{"cve":{"cve_id":"CVE-2026-47270","is_kev":false,"kev_date_added":null,"kev_vendor_project":null,"kev_product":null,"kev_vulnerability_name":null,"kev_short_description":null,"kev_required_action":null,"kev_due_date":null,"kev_known_ransomware":null,"kev_notes":null,"kev_cwes":null,"epss_score":0.00108,"epss_percentile":0.01425,"epss_as_of":"2026-06-23","description":"pam_usb provides hardware authentication for Linux using ordinary removable media. Prior to 0.9.0, pam_usb is a PAM module loaded into the host process (sudo, login, GDM, GNOME Shell). Display managers such as GDM run multiple concurrent authentication threads. Three functions used by the deny_remote feature called the non-reentrant strtok(), which stores state in a single global pointer. If two authentications race, one thread's strtok() call can overwrite the other's in-progress tokenisation pointer, causing incorrect parsing of the tmux session data or the /proc environ scan that backs the remote-session detection logic. Additionally, pusb_tmux_get_client_tty() passed the raw pointer returned by getenv(TMUX) directly to strtok(). getenv() returns a pointer into the live process environment block; strtok() inserts NUL bytes into that block, permanently corrupting the TMUX variable for subsequent code running in the same process. In long-lived display managers this affects all future authentications in that process. The combined effect can cause deny_remote=true to return an incorrect decision for a remote session, or an incorrect decision for a local session, depending on thread interleaving. This vulnerability is fixed in 0.9.0.","published_at":"2026-05-27T20:10:37.108000Z","last_modified_at":null,"cvss_v3_score":6.3,"cvss_v3_vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:N","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":null,"ssvc_automatable":null,"ssvc_technical_impact":null,"cwes":["CWE-362"],"nvd_references":["https://github.com/mcdope/pam_usb/security/advisories/GHSA-j3xw-vc43-x7jg","https://github.com/mcdope/pam_usb/commit/94f1640a61d49dfaf38e782680a52f01d5bf8b51","https://github.com/mcdope/pam_usb/commit/d003e551b794a9e3774ff4720830fb7aadaa48bd"],"vuln_status":null,"trending_score":null,"is_trending":false,"has_trended":false,"trended_number_one":false,"trending_peak_score":null,"trending_peak_rank":null,"started_trending_at":null,"trended_number_one_at":null,"summary_generated":null,"summary_generated_at":null,"summary_model":null,"created_at":"2026-06-24T00:09:39.878444Z","updated_at":"2026-06-28T23:30:40.878937Z"},"effective_severity":"MEDIUM","badges":[],"impact_analysis":[],"cvss_v3_decoded":{"version":"3.1","metrics":[{"metric":"AV","name":"Attack Vector","value":"L","value_label":"Local"},{"metric":"AC","name":"Attack Complexity","value":"H","value_label":"High"},{"metric":"PR","name":"Privileges Required","value":"L","value_label":"Low"},{"metric":"UI","name":"User Interaction","value":"N","value_label":"None"},{"metric":"S","name":"Scope","value":"U","value_label":"Unchanged"},{"metric":"C","name":"Confidentiality","value":"H","value_label":"High"},{"metric":"I","name":"Integrity","value":"H","value_label":"High"},{"metric":"A","name":"Availability","value":"N","value_label":"None"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"mcdope","vendor_name":"mcdope","product_slug":"pam-usb","product_name":"pam_usb","version_start":"< 0.9.0","version_start_inclusive":true,"version_end":"< 0.9.0","version_end_inclusive":true,"cpe23_uri":"cve5:mcdope:pam-usb:< 0.9.0:< 0.9.0"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/mcdope/pam_usb/security/advisories/GHSA-j3xw-vc43-x7jg","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/mcdope/pam_usb/commit/94f1640a61d49dfaf38e782680a52f01d5bf8b51","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/mcdope/pam_usb/commit/d003e551b794a9e3774ff4720830fb7aadaa48bd","source_type":"PATCH","tags":["patch"]}],"timeline":[{"type":"published","at":"2026-05-27T20:10:37.108000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:54:57.553414Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:54:57.553414Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:54:57.553414Z","label":"CVSS score revised","source":"cvelistv5"}]}