{"id":"CVE-2026-21916","state":"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.","publishedAt":"2026-04-09T21:28:05.552Z","updatedAt":"2026-04-13T13:04:16.395Z","severity":{"score":7,"label":"High","version":"4.0","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","source":"juniper"},"assigner":"juniper","products":["Juniper Networks Junos OS"],"affected":[{"vendor":"Juniper Networks","product":"Junos OS","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"23.2R2-S7","versionType":"semver"},{"version":"23.4","status":"affected","lessThan":"23.4R2-S6","versionType":"semver"},{"version":"24.2","status":"affected","lessThan":"24.2R2-S3","versionType":"semver"},{"version":"24.4","status":"affected","lessThan":"24.4R2-S2","versionType":"semver"},{"version":"25.2","status":"affected","lessThan":"25.2R2","versionType":"semver"},{"version":"25.4R1","status":"unaffected"}]}],"references":["https://kb.juniper.net/JSA107807"],"weaknesses":["CWE-61"],"ingestedAt":"2026-10-29T20:11:10.572Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/21xxx/CVE-2026-21916.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-21916","state":"PUBLISHED","datePublished":"2026-04-09T21:28:05.552Z","dateUpdated":"2026-04-13T13:04:16.395Z","assignerShortName":"juniper","assignerOrgId":"8cbe9d5a-a066-4c94-8978-4b15efeae968","dateReserved":"2026-01-05T17:32:48.711Z"},"containers":{"cna":{"title":"Junos OS: A low privileged user can escalate their privileges so that they can login as root","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Juniper Networks","product":"Junos OS","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"23.2R2-S7","versionType":"semver"},{"version":"23.4","status":"affected","lessThan":"23.4R2-S6","versionType":"semver"},{"version":"24.2","status":"affected","lessThan":"24.2R2-S3","versionType":"semver"},{"version":"24.4","status":"affected","lessThan":"24.4R2-S2","versionType":"semver"},{"version":"25.2","status":"affected","lessThan":"25.2R2","versionType":"semver"},{"version":"25.4R1","status":"unaffected"}]}],"references":[{"url":"https://kb.juniper.net/JSA107807","tags":["vendor-advisory"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"LOCAL","availabilityImpact":"HIGH","baseScore":7.3,"baseSeverity":"HIGH","confidentialityImpact":"HIGH","integrityImpact":"HIGH","privilegesRequired":"LOW","scope":"UNCHANGED","userInteraction":"REQUIRED","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H","version":"3.1"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]},{"cvssV4_0":{"Automatable":"YES","Recovery":"USER","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"LOCAL","baseScore":7,"baseSeverity":"HIGH","privilegesRequired":"LOW","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"PASSIVE","valueDensity":"NOT_DEFINED","vectorString":"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","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"HIGH","vulnIntegrityImpact":"HIGH","vulnerabilityResponseEffort":"MODERATE"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-61","description":"CWE-61 UNIX Symbolic Link (Symlink) Following","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"juniper","orgId":"8cbe9d5a-a066-4c94-8978-4b15efeae968","dateUpdated":"2026-04-09T21:28:05.552Z"},"datePublic":"2026-04-08T16:00:00.000Z","exploits":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"Juniper SIRT is not aware of any malicious exploitation of this vulnerability."}],"value":"Juniper SIRT is not aware of any malicious exploitation of this vulnerability."}],"solutions":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"The following software releases have been updated to resolve this specific issue: 23.2R2-S7, 23.4R2-S6, 24.2R2-S3, 24.4R2-S2, 25.2R2, and all subsequent releases.<br>"}],"value":"The following software releases have been updated to resolve this specific issue: 23.2R2-S7, 23.4R2-S6, 24.2R2-S3, 24.4R2-S2, 25.2R2, and all subsequent releases."}],"source":{"advisory":"JSA107807","defect":["1865633"],"discovery":"EXTERNAL"},"workarounds":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"To prevent exploitation, use access controls to keep users from performing 'file link' operations."}],"value":"To prevent exploitation, use access controls to keep users from performing 'file link' operations."}],"x_generator":{"engine":"Vulnogram 0.1.0-dev"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-21916","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-04-10T03:56:11.604149Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-13T13:04:16.395Z"}}]}}}