{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-21901", "assignerOrgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968", "state": "PUBLISHED", "assignerShortName": "juniper", "dateReserved": "2026-01-05T17:32:48.709Z", "datePublished": "2026-07-09T21:01:31.334Z", "dateUpdated": "2026-07-09T21:01:31.334Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Junos OS", "vendor": "Juniper Networks", "versions": [{"lessThan": "22.3R3-S5", "status": "affected", "version": "22.3", "versionType": "custom"}, {"lessThan": "22.4R3-S10", "status": "affected", "version": "22.4", "versionType": "custom"}, {"lessThan": "23.2R2-S7", "status": "affected", "version": "23.2", "versionType": "custom"}, {"lessThan": "23.4R2-S8", "status": "affected", "version": "23.4", "versionType": "custom"}, {"lessThan": "22.3R1", "status": "unaffected", "version": "0", "versionType": "custom"}]}, {"defaultStatus": "unaffected", "product": "Junos OS Evolved", "vendor": "Juniper Networks", "versions": [{"lessThan": "23.2R2-S7-EVO", "status": "affected", "version": "23.2", "versionType": "custom"}, {"lessThan": "23.4R2-S8-EVO", "status": "affected", "version": "23.4", "versionType": "custom"}, {"lessThan": "22.3R1-EVO", "status": "unaffected", "version": "0", "versionType": "custom"}]}], "credits": [{"lang": "en", "type": "finder", "value": "Juniper SIRT would like to acknowledge and thank Orange CERT-CC from the Orange group for responsibly reporting this vulnerability."}], "datePublic": "2026-07-08T16:00:00.000Z", "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "A NULL Pointer Dereference vulnerability in the management daemon (mgd) of Juniper Networks Junos OS and Junos OS Evolved allows a local, high-privileged attacker setting or deactivating a&nbsp;specific SSH configuration parameter to create a Denial of Service (DoS).<br><br>A local high-privileged user configuring or deactivating a specific 'system services ssh' configuration parameter&nbsp;can exploit a null pointer dereference in one of the functions used by SSH. The function attempts to dereference a null pointer when accessing certain configuration data, resulting in an mgd process crash and restart.&nbsp;Continued execution of these configuration commands will create a sustained Denial of Service (DoS) condition.<br><p><br>This issue affects:<br>Junos OS:<br></p><ul><li>from 22.3 before 22.3R3-S5;</li><li>from 22.4 before 22.4R3-S10;</li><li>from 23.2 before 23.2R2-S7;</li><li>from 23.4 before 23.4R2-S8.</li></ul>\n\nThis issue does not affect Junos OS before 22.3R1.\n\n<br><br>Junos OS Evolved:<br><ul><li>from 22.3R1-EVO before 23.2R2-S7-EVO;</li><li>from 23.4 before 23.4R2-S8-EVO.</li></ul>This issue does not affect Junos OS Evolved before 22.3R1-EVO.<p></p>"}], "value": "A NULL Pointer Dereference vulnerability in the management daemon (mgd) of Juniper Networks Junos OS and Junos OS Evolved allows a local, high-privileged attacker setting or deactivating a\u00a0specific SSH configuration parameter to create a Denial of Service (DoS).\n\nA local high-privileged user configuring or deactivating a specific 'system services ssh' configuration parameter\u00a0can exploit a null pointer dereference in one of the functions used by SSH. The function attempts to dereference a null pointer when accessing certain configuration data, resulting in an mgd process crash and restart.\u00a0Continued execution of these configuration commands will create a sustained Denial of Service (DoS) condition.\n\nThis issue affects:\nJunos OS:\n\n\n * from 22.3 before 22.3R3-S5;\n * from 22.4 before 22.4R3-S10;\n * from 23.2 before 23.2R2-S7;\n * from 23.4 before 23.4R2-S8.\n\n\n\n\nThis issue does not affect Junos OS before 22.3R1.\n\n\n\nJunos OS Evolved:\n * from 22.3R1-EVO before 23.2R2-S7-EVO;\n * from 23.4 before 23.4R2-S8-EVO.\n\n\nThis issue does not affect Junos OS Evolved before 22.3R1-EVO."}], "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."}], "metrics": [{"cvssV3_1": {"attackComplexity": "LOW", "attackVector": "LOCAL", "availabilityImpact": "HIGH", "baseScore": 4.4, "baseSeverity": "MEDIUM", "confidentialityImpact": "NONE", "integrityImpact": "NONE", "privilegesRequired": "HIGH", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:H/UI:N/S:U/C:N/I:N/A:H", "version": "3.1"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"cvssV4_0": {"Automatable": "YES", "Recovery": "AUTOMATIC", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "NONE", "attackVector": "LOCAL", "baseScore": 6.7, "baseSeverity": "MEDIUM", "privilegesRequired": "HIGH", "providerUrgency": "GREEN", "subAvailabilityImpact": "NONE", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "DIFFUSE", "vectorString": "CVSS:4.0/AV:L/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/AU:Y/R:A/V:D/RE:M/U:Green", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "NONE", "vulnIntegrityImpact": "NONE", "vulnerabilityResponseEffort": "MODERATE"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-476", "description": "CWE-476 NULL Pointer Dereference", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968", "shortName": "juniper", "dateUpdated": "2026-07-09T21:01:31.334Z"}, "references": [{"tags": ["third-party-advisory"], "url": "https://github.com/orangecertcc/security-research/security/advisories/GHSA-g4f7-w2rc-hpj6"}, {"tags": ["vendor-advisory"], "url": "https://supportportal.juniper.net/JSA110072"}], "solutions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "The following software releases have been updated to resolve this specific issue:<br>Junos OS: 22.3R3-S5, 22.4R3-S10, 23.2R2-S7, 23.4R2-S8, 24.2R1, and all subsequent releases.\n<br>\nJunos OS Evolved: 23.2R2-S7-EVO, 23.4R2-S8-EVO, 24.2R1-EVO, and all subsequent releases."}], "value": "The following software releases have been updated to resolve this specific issue:\nJunos OS: 22.3R3-S5, 22.4R3-S10, 23.2R2-S7, 23.4R2-S8, 24.2R1, and all subsequent releases.\n\n\nJunos OS Evolved: 23.2R2-S7-EVO, 23.4R2-S8-EVO, 24.2R1-EVO, and all subsequent releases."}], "source": {"advisory": "JSA110072", "defect": ["1779319"], "discovery": "EXTERNAL"}, "title": "Junos OS and Junos OS Evolved: Configuration of a specific SSH option results in mgd crash", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "<span style=\"background-color: rgb(255, 255, 255);\">There are no direct workarounds for this issue.<br><br>\n\n<span style=\"background-color: rgb(255, 255, 255);\">One of the following mitigations will prevent malicious exploitation:</span><br><ul></ul><ul></ul><ul><li>Use access lists or firewall filters to limit access to the CLI only from trusted hosts and administrators.</li><li>Utilize command authorization to limit the ability to enter config mode to trusted administrators.</li></ul></span>"}], "value": "There are no direct workarounds for this issue.\n\n\n\nOne of the following mitigations will prevent malicious exploitation:\n\n\n\n\n * Use access lists or firewall filters to limit access to the CLI only from trusted hosts and administrators.\n * Utilize command authorization to limit the ability to enter config mode to trusted administrators."}], "x_generator": {"engine": "Vulnogram 0.1.0-dev"}}}}

{}

{}

{}

{}