{"id":"CVE-2026-21916","aliases":["EUVD-2026-21080","GHSA-x5g9-73r3-vh5h"],"status":"published","title":"Junos OS: A low privileged user can escalate their privileges so that they can login as root","description":"A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system.\n\nWhen after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root.\n\nThis issue affects Junos OS:\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S6,\n  *  24.2 versions before 24.2R2-S3,\n  *  24.4 versions before 24.4R2-S2,\n  *  25.2 versions before 25.2R2.\n\n\nThis issue does not affect versions 25.4R1 or later.","severity":{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-12","score":0.00131,"percentile":0.02765,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-61"],"published":"2026-04-09T21:28:05Z","modified":"2026-10-26T21:10:00Z","products":[{"vendor":"juniper","product":"junos"},{"vendor":"juniper networks","product":"junos os"}],"references":[{"url":"https://kb.juniper.net/JSA107807","tags":["vendor-advisory","Mitigation","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2026-21916"},{"url":"https://github.com/advisories/GHSA-x5g9-73r3-vh5h"}],"sources":{"cve":[{"id":"CVE-2026-21916","title":"Junos OS: A low privileged user can escalate their privileges so that they can login as root","description":"A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system.\n\nWhen after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root.\n\nThis issue affects Junos OS:\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S6,\n  *  24.2 versions before 24.2R2-S3,\n  *  24.4 versions before 24.4R2-S2,\n  *  25.2 versions before 25.2R2.\n\n\nThis issue does not affect versions 25.4R1 or later.","status":"published","published":"2026-04-09T21:28:05.552Z","modified":"2026-04-13T13:04:16.395Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M","level":"high","assessor":"cna"},{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-61"],"updated_at":"2026-11-02T13:41:53.237769Z"}],"euvd":[{"id":"EUVD-2026-21080","description":"A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system.\n\nWhen after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root.\n\nThis issue affects Junos OS:\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S6,\n  *  24.2 versions before 24.2R2-S3,\n  *  24.4 versions before 24.4R2-S2,\n  *  25.2 versions before 25.2R2.\n\n\nThis issue does not affect versions 25.4R1 or later.","status":"published","published":"2026-04-09T21:28:05Z","modified":"2026-04-13T13:04:16Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/AU:Y/R:U/RE:M","level":"high"}],"updated_at":"2026-11-02T19:24:29.371024Z"}],"ghsa":[{"id":"GHSA-x5g9-73r3-vh5h","title":"A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS...","description":"A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system.\n\nWhen after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root.\n\nThis issue affects Junos OS:\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S6,\n  *  24.2 versions before 24.2R2-S3,\n  *  24.4 versions before 24.4R2-S2,\n  *  25.2 versions before 25.2R2.\n\n\nThis issue does not affect versions 25.4R1 or later.","status":"published","published":"2026-04-10T00:30:29Z","modified":"2026-04-10T00:30:37Z","cvss":[{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high"},{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:X/RE:M/U:X","level":"high"}],"cwes":["CWE-61"],"updated_at":"2026-11-02T15:07:24.354029Z"}],"nvd":[{"id":"CVE-2026-21916","description":"A UNIX Symbolic Link (Symlink) Following vulnerability in the CLI of Juniper Networks Junos OS allows a local, authenticated attacker with low privileges to escalate their privileges to root which will lead to a complete compromise of the system.\n\nWhen after a user has performed a specific 'file link ...' CLI operation, another user commits (unrelated configuration changes), the first user can login as root.\n\nThis issue affects Junos OS:\n  *  all versions before 23.2R2-S7,\n  *  23.4 versions before 23.4R2-S6,\n  *  24.2 versions before 24.2R2-S3,\n  *  24.4 versions before 24.4R2-S2,\n  *  25.2 versions before 25.2R2.\n\n\nThis issue does not affect versions 25.4R1 or later.","status":"published","published":"2026-04-09T22:16:24.953Z","modified":"2026-10-26T21:10:00.17Z","cvss":[{"version":"4.0","score":7,"vector":"CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:P/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:U/V:X/RE:M/U:X","level":"high","assessor":"secondary"},{"version":"3.1","score":7.3,"vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","level":"high","assessor":"secondary"}],"cwes":["CWE-61"],"updated_at":"2026-11-02T14:12:13.902911Z"}]}}