{"cve":{"cve_id":"CVE-2026-27456","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":0.00118,"epss_percentile":0.01882,"epss_as_of":"2026-08-26","description":"util-linux is a random collection of Linux utilities. Prior to version 2.41.4, a TOCTOU (Time-of-Check-Time-of-Use) vulnerability has been identified in the SUID binary /usr/bin/mount from util-linux. The mount binary, when setting up loop devices, validates the source file path with user privileges via fork() + setuid() + realpath(), but subsequently re-canonicalizes and opens it with root privileges (euid=0) without verifying that the path has not been replaced between both operations. Neither O_NOFOLLOW, nor inode comparison, nor post-open fstat() are employed. This allows a local unprivileged user to replace the source file with a symlink pointing to any root-owned file or device during the race window, causing the SUID binary to open and mount it as root. Exploitation requires an /etc/fstab entry with user,loop options whose path points to a directory where the attacker has write permission, and that /usr/bin/mount has the SUID bit set (the default configuration on virtually all Linux distributions). The impact is unauthorized read access to root-protected files and block devices, including backup images, disk volumes, and any file containing a valid filesystem. This issue has been patched in version 2.41.4.","published_at":"2026-04-03T21:23:00.984000Z","last_modified_at":"2026-07-24T22:10:00.140000Z","cvss_v3_score":4.7,"cvss_v3_vector":"CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:N/A:N","cvss_v3_severity":"MEDIUM","cvss_v4_score":null,"cvss_v4_vector":null,"cvss_v4_severity":null,"ssvc_decision":null,"ssvc_exploitation":"poc","ssvc_automatable":false,"ssvc_technical_impact":"partial","cwes":["CWE-59","CWE-269","CWE-367"],"nvd_references":["https://github.com/util-linux/util-linux/security/advisories/GHSA-qq4x-vfq4-9h9g","https://github.com/util-linux/util-linux/commit/5e390467b26a3cf3fecc04e1a0d482dff3162fc4","https://github.com/util-linux/util-linux/releases/tag/v2.41.4"],"vuln_status":"Analyzed","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":"2026-07-25T10:43:48.220773Z"},"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":"N","value_label":"None"},{"metric":"A","name":"Availability","value":"N","value_label":"None"}]},"cvss_v4_decoded":{"version":null,"metrics":[]},"affected":[{"vendor_slug":"kernel","vendor_name":"kernel","product_slug":"util-linux","product_name":"util-linux","version_start":null,"version_start_inclusive":null,"version_end":"2.41.4","version_end_inclusive":false,"cpe23_uri":"cpe:2.3:a:kernel:util-linux:*:*:*:*:*:*:*:*"},{"vendor_slug":"util-linux","vendor_name":"util-linux","product_slug":"util-linux","product_name":"util-linux","version_start":"< 2.41.4","version_start_inclusive":true,"version_end":"< 2.41.4","version_end_inclusive":true,"cpe23_uri":"cve5:util-linux:util-linux:< 2.41.4:< 2.41.4"}],"exploit_refs":[],"news":[],"references":[{"url":"https://github.com/util-linux/util-linux/security/advisories/GHSA-qq4x-vfq4-9h9g","source_type":"VENDOR_ADVISORY","tags":["advisory"]},{"url":"https://github.com/util-linux/util-linux/commit/5e390467b26a3cf3fecc04e1a0d482dff3162fc4","source_type":"PATCH","tags":["patch"]},{"url":"https://github.com/util-linux/util-linux/releases/tag/v2.41.4","source_type":"PATCH","tags":["patch"]}],"timeline":[{"type":"published","at":"2026-04-03T21:23:00.984000Z","label":"CVE published","source":null},{"type":"cvss_changed","at":"2026-06-28T17:52:22.671512Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:52:22.671512Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"cvss_changed","at":"2026-06-28T17:52:22.671512Z","label":"CVSS score revised","source":"cvelistv5"},{"type":"ssvc_changed","at":"2026-06-29T23:46:59.033383Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T23:46:59.033383Z","label":"SSVC decision revised","source":"vulnrichment"},{"type":"ssvc_changed","at":"2026-06-29T23:46:59.033383Z","label":"SSVC decision revised","source":"vulnrichment"}]}