CVE-2026-21908

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For example:<br><br><tt>[protocols dot1x authenticator ...]</tt>"}], "value": "This issue requires support for 802.1X be enabled. For example:\n\n[protocols dot1x authenticator ...]"}], "datePublic": "2026-01-14T17:00:00.000Z", "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "A Use After Free vulnerability was identified in the 802.1X authentication daemon (dot1xd) of&nbsp;Juniper Networks Junos OS and Junos OS Evolved that could allow an authenticated, network-adjacent attacker flapping a port to crash the dot1xd process, leading to a Denial of Service (DoS), or potentially execute arbitrary code within the context of the process running as root.<br><br>The issue is specific to the processing of a change in authorization (CoA) when a port bounce occurs. A pointer is freed but was then referenced later in the same code path. Successful exploitation is outside the attacker's direct control due to the specific timing of the two events required to execute the vulnerable code path.<br><br>This issue affects systems with 802.1X authentication port-based network access control (PNAC) enabled.<br><p>This issue affects:</p><p>Junos OS:&nbsp;</p><p></p><ul><li>from 23.2R2-S1 before 23.2R2-S5,&nbsp;</li><li>from 23.4R2 before 23.4R2-S6,&nbsp;</li><li>from 24.2 before 24.2R2-S3,&nbsp;</li><li>from 24.4 before 24.4R2-S1,&nbsp;</li><li>from 25.2 before 25.2R1-S2, 25.2R2;&nbsp;</li></ul><p></p><p>Junos OS Evolved:&nbsp;</p><p></p><ul><li>from 23.2R2-S1 before 23.2R2-S5-EVO,&nbsp;</li><li>from 23.4R2 before 23.4R2-S6-EVO,&nbsp;</li><li>from 24.2 before 24.2R2-S3-EVO,&nbsp;</li><li>from 24.4 before 24.4R2-S1-EVO,&nbsp;</li><li>from 25.2 before 25.2R1-S2-EVO, 25.2R2-EVO.</li></ul><p></p>"}], "value": "A Use After Free vulnerability was identified in the 802.1X authentication daemon (dot1xd) of\u00a0Juniper Networks Junos OS and Junos OS Evolved that could allow an authenticated, network-adjacent attacker flapping a port to crash the dot1xd process, leading to a Denial of Service (DoS), or potentially execute arbitrary code within the context of the process running as root.\n\nThe issue is specific to the processing of a change in authorization (CoA) when a port bounce occurs. A pointer is freed but was then referenced later in the same code path. Successful exploitation is outside the attacker's direct control due to the specific timing of the two events required to execute the vulnerable code path.\n\nThis issue affects systems with 802.1X authentication port-based network access control (PNAC) enabled.\nThis issue affects:\n\nJunos OS:\u00a0\n\n\n\n * from 23.2R2-S1 before 23.2R2-S5,\u00a0\n * from 23.4R2 before 23.4R2-S6,\u00a0\n * from 24.2 before 24.2R2-S3,\u00a0\n * from 24.4 before 24.4R2-S1,\u00a0\n * from 25.2 before 25.2R1-S2, 25.2R2;\u00a0\n\n\n\n\nJunos OS Evolved:\u00a0\n\n\n\n * from 23.2R2-S1 before 23.2R2-S5-EVO,\u00a0\n * from 23.4R2 before 23.4R2-S6-EVO,\u00a0\n * from 24.2 before 24.2R2-S3-EVO,\u00a0\n * from 24.4 before 24.4R2-S1-EVO,\u00a0\n * from 25.2 before 25.2R1-S2-EVO, 25.2R2-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": "HIGH", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "ADJACENT", "baseScore": 7.5, "baseSeverity": "HIGH", "privilegesRequired": "LOW", "providerUrgency": "GREEN", "subAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/RE:M/U:Green", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "MODERATE"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-416", "description": "CWE-416 Use After Free", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968", "shortName": "juniper", "dateUpdated": "2026-01-15T20:21:41.576Z"}, "references": [{"tags": ["vendor-advisory"], "url": "https://supportportal.juniper.net/JSA106007"}, {"tags": ["vendor-advisory"], "url": "https://kb.juniper.net/JSA106007"}], "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 23.2R2-S5, 23.4R2-S6, 24.2R2-S3, 24.4R2-S1, 25.2R1-S2, 25.2R2, 25.4R1, and all subsequent releases.<br>Junos OS Evolved:&nbsp;23.2R2-S5-EVO, 23.4R2-S6-EVO, 24.2R2-S3-EVO, 24.4R2-S1-EVO, 25.2R1-S2-EVO, 25.2R2-EVO, 25.4R1-EVO,"}], "value": "The following software releases have been updated to resolve this specific issue:\nJunos OS 23.2R2-S5, 23.4R2-S6, 24.2R2-S3, 24.4R2-S1, 25.2R1-S2, 25.2R2, 25.4R1, and all subsequent releases.\nJunos OS Evolved:\u00a023.2R2-S5-EVO, 23.4R2-S6-EVO, 24.2R2-S3-EVO, 24.4R2-S1-EVO, 25.2R1-S2-EVO, 25.2R2-EVO, 25.4R1-EVO,"}], "source": {"advisory": "JSA106007", "defect": ["1896371"], "discovery": "INTERNAL"}, "title": "Junos OS and Junos OS Evolved: Use after free vulnerability In 802.1X authentication daemon can cause crash of the dot1xd process", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "There are no known workarounds for this issue."}], "value": "There are no known workarounds for this issue."}], "x_generator": {"engine": "Vulnogram 0.1.0-dev"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-21908", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-01-16T04:55:55.863089Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-02-26T15:04:06.477Z"}}]}}

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-21908", "assignerOrgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968", "state": "PUBLISHED", "assignerShortName": "juniper", "dateReserved": "2026-01-05T17:32:48.710Z", "datePublished": "2026-01-15T20:21:41.576Z", "dateUpdated": "2026-01-16T04:55:55.090Z"}, "containers": {"cna": {"affected": [{"defaultStatus": "unaffected", "product": "Junos OS", "vendor": "Juniper Networks", "versions": [{"lessThan": "23.2R2-S5", "status": "affected", "version": "23.2R2-S1", "versionType": "semver"}, {"lessThan": "23.4R2-S6", "status": "affected", "version": "23.4R2", "versionType": "semver"}, {"lessThan": "24.2R2-S3", "status": "affected", "version": "24.2", "versionType": "semver"}, {"lessThan": "24.4R2-S1", "status": "affected", "version": "24.4", "versionType": "semver"}, {"lessThan": "25.2R1-S2, 25.2R2", "status": "affected", "version": "25.2", "versionType": "semver"}]}, {"defaultStatus": "unaffected", "product": "Junos OS Evolved", "vendor": "Juniper Networks", "versions": [{"lessThan": "23.2R2-S5-EVO", "status": "affected", "version": "23.2R2-S1", "versionType": "semver"}, {"lessThan": "23.4R2-S6-EVO", "status": "affected", "version": "23.4R2", "versionType": "semver"}, {"lessThan": "24.2R2-S3-EVO", "status": "affected", "version": "24.2", "versionType": "semver"}, {"lessThan": "24.4R2-S1-EVO", "status": "affected", "version": "24.4", "versionType": "semver"}, {"lessThan": "25.2R1-S2-EVO, 25.2R2-EVO", "status": "affected", "version": "25.2", "versionType": "semver"}]}], "configurations": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "This issue requires support for 802.1X be enabled. For example:<br><br><tt>[protocols dot1x authenticator ...]</tt>"}], "value": "This issue requires support for 802.1X be enabled. For example:\n\n[protocols dot1x authenticator ...]"}], "datePublic": "2026-01-14T17:00:00.000Z", "descriptions": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "A Use After Free vulnerability was identified in the 802.1X authentication daemon (dot1xd) of&nbsp;Juniper Networks Junos OS and Junos OS Evolved that could allow an authenticated, network-adjacent attacker flapping a port to crash the dot1xd process, leading to a Denial of Service (DoS), or potentially execute arbitrary code within the context of the process running as root.<br><br>The issue is specific to the processing of a change in authorization (CoA) when a port bounce occurs. A pointer is freed but was then referenced later in the same code path. Successful exploitation is outside the attacker's direct control due to the specific timing of the two events required to execute the vulnerable code path.<br><br>This issue affects systems with 802.1X authentication port-based network access control (PNAC) enabled.<br><p>This issue affects:</p><p>Junos OS:&nbsp;</p><p></p><ul><li>from 23.2R2-S1 before 23.2R2-S5,&nbsp;</li><li>from 23.4R2 before 23.4R2-S6,&nbsp;</li><li>from 24.2 before 24.2R2-S3,&nbsp;</li><li>from 24.4 before 24.4R2-S1,&nbsp;</li><li>from 25.2 before 25.2R1-S2, 25.2R2;&nbsp;</li></ul><p></p><p>Junos OS Evolved:&nbsp;</p><p></p><ul><li>from 23.2R2-S1 before 23.2R2-S5-EVO,&nbsp;</li><li>from 23.4R2 before 23.4R2-S6-EVO,&nbsp;</li><li>from 24.2 before 24.2R2-S3-EVO,&nbsp;</li><li>from 24.4 before 24.4R2-S1-EVO,&nbsp;</li><li>from 25.2 before 25.2R1-S2-EVO, 25.2R2-EVO.</li></ul><p></p>"}], "value": "A Use After Free vulnerability was identified in the 802.1X authentication daemon (dot1xd) of\u00a0Juniper Networks Junos OS and Junos OS Evolved that could allow an authenticated, network-adjacent attacker flapping a port to crash the dot1xd process, leading to a Denial of Service (DoS), or potentially execute arbitrary code within the context of the process running as root.\n\nThe issue is specific to the processing of a change in authorization (CoA) when a port bounce occurs. A pointer is freed but was then referenced later in the same code path. Successful exploitation is outside the attacker's direct control due to the specific timing of the two events required to execute the vulnerable code path.\n\nThis issue affects systems with 802.1X authentication port-based network access control (PNAC) enabled.\nThis issue affects:\n\nJunos OS:\u00a0\n\n\n\n * from 23.2R2-S1 before 23.2R2-S5,\u00a0\n * from 23.4R2 before 23.4R2-S6,\u00a0\n * from 24.2 before 24.2R2-S3,\u00a0\n * from 24.4 before 24.4R2-S1,\u00a0\n * from 25.2 before 25.2R1-S2, 25.2R2;\u00a0\n\n\n\n\nJunos OS Evolved:\u00a0\n\n\n\n * from 23.2R2-S1 before 23.2R2-S5-EVO,\u00a0\n * from 23.4R2 before 23.4R2-S6-EVO,\u00a0\n * from 24.2 before 24.2R2-S3-EVO,\u00a0\n * from 24.4 before 24.4R2-S1-EVO,\u00a0\n * from 25.2 before 25.2R1-S2-EVO, 25.2R2-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": "HIGH", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}, {"cvssV4_0": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "ADJACENT", "baseScore": 7.5, "baseSeverity": "HIGH", "privilegesRequired": "LOW", "providerUrgency": "GREEN", "subAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:L/RE:M/U:Green", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "MODERATE"}, "format": "CVSS", "scenarios": [{"lang": "en", "value": "GENERAL"}]}], "problemTypes": [{"descriptions": [{"cweId": "CWE-416", "description": "CWE-416 Use After Free", "lang": "en", "type": "CWE"}]}], "providerMetadata": {"orgId": "8cbe9d5a-a066-4c94-8978-4b15efeae968", "shortName": "juniper", "dateUpdated": "2026-01-15T20:21:41.576Z"}, "references": [{"tags": ["vendor-advisory"], "url": "https://supportportal.juniper.net/JSA106007"}, {"tags": ["vendor-advisory"], "url": "https://kb.juniper.net/JSA106007"}], "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 23.2R2-S5, 23.4R2-S6, 24.2R2-S3, 24.4R2-S1, 25.2R1-S2, 25.2R2, 25.4R1, and all subsequent releases.<br>Junos OS Evolved:&nbsp;23.2R2-S5-EVO, 23.4R2-S6-EVO, 24.2R2-S3-EVO, 24.4R2-S1-EVO, 25.2R1-S2-EVO, 25.2R2-EVO, 25.4R1-EVO,"}], "value": "The following software releases have been updated to resolve this specific issue:\nJunos OS 23.2R2-S5, 23.4R2-S6, 24.2R2-S3, 24.4R2-S1, 25.2R1-S2, 25.2R2, 25.4R1, and all subsequent releases.\nJunos OS Evolved:\u00a023.2R2-S5-EVO, 23.4R2-S6-EVO, 24.2R2-S3-EVO, 24.4R2-S1-EVO, 25.2R1-S2-EVO, 25.2R2-EVO, 25.4R1-EVO,"}], "source": {"advisory": "JSA106007", "defect": ["1896371"], "discovery": "INTERNAL"}, "title": "Junos OS and Junos OS Evolved: Use after free vulnerability In 802.1X authentication daemon can cause crash of the dot1xd process", "workarounds": [{"lang": "en", "supportingMedia": [{"base64": false, "type": "text/html", "value": "There are no known workarounds for this issue."}], "value": "There are no known workarounds for this issue."}], "x_generator": {"engine": "Vulnogram 0.1.0-dev"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-21908", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "no"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-01-16T04:55:55.863089Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-01-15T20:45:01.036Z"}, "title": "CISA ADP Vulnrichment"}]}}

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After Free vulnerability was identified in the 802.1X authentication daemon (dot1xd) of\u00a0Juniper Networks Junos OS and Junos OS Evolved that could allow an authenticated, network-adjacent attacker flapping a port to crash the dot1xd process, leading to a Denial of Service (DoS), or potentially execute arbitrary code within the context of the process running as root.\n\nThe issue is specific to the processing of a change in authorization (CoA) when a port bounce occurs. A pointer is freed but was then referenced later in the same code path. Successful exploitation is outside the attacker's direct control due to the specific timing of the two events required to execute the vulnerable code path.\n\nThis issue affects systems with 802.1X authentication port-based network access control (PNAC) enabled.\nThis issue affects:\n\nJunos OS:\u00a0\n\n\n\n * from 23.2R2-S1 before 23.2R2-S5,\u00a0\n * from 23.4R2 before 23.4R2-S6,\u00a0\n * from 24.2 before 24.2R2-S3,\u00a0\n * from 24.4 before 24.4R2-S1,\u00a0\n * from 25.2 before 25.2R1-S2, 25.2R2;\u00a0\n\n\n\n\nJunos OS Evolved:\u00a0\n\n\n\n * from 23.2R2-S1 before 23.2R2-S5-EVO,\u00a0\n * from 23.4R2 before 23.4R2-S6-EVO,\u00a0\n * from 24.2 before 24.2R2-S3-EVO,\u00a0\n * from 24.4 before 24.4R2-S1-EVO,\u00a0\n * from 25.2 before 25.2R1-S2-EVO, 25.2R2-EVO."}, {"lang": "es", "value": "Una vulnerabilidad de Use After Free fue identificada en el demonio de autenticaci\u00f3n 802.1X (dot1xd) de Juniper Networks Junos OS y Junos OS Evolved que podr\u00eda permitir a un atacante autenticado y adyacente a la red, alternando un puerto, bloquear el proceso dot1xd, lo que lleva a una denegaci\u00f3n de servicio (DoS), o potencialmente ejecutar c\u00f3digo arbitrario dentro del contexto del proceso que se ejecuta como root.\n\nEl problema es espec\u00edfico del procesamiento de un cambio en la autorizaci\u00f3n (CoA) cuando ocurre un rebote de puerto. Un puntero es liberado pero luego fue referenciado m\u00e1s tarde en la misma ruta de c\u00f3digo. La explotaci\u00f3n exitosa est\u00e1 fuera del control directo del atacante debido a la sincronizaci\u00f3n espec\u00edfica de los dos eventos requeridos para ejecutar la ruta de c\u00f3digo vulnerable.\n\nEste problema afecta a sistemas con autenticaci\u00f3n 802.1X con control de acceso a la red basado en puerto (PNAC) habilitado.\nEste problema afecta a:\n\nJunos OS:\n\n * desde 23.2R2-S1 antes de 23.2R2-S5,\n * desde 23.4R2 antes de 23.4R2-S6,\n * desde 24.2 antes de 24.2R2-S3,\n * desde 24.4 antes de 24.4R2-S1,\n * desde 25.2 antes de 25.2R1-S2, 25.2R2;\n\nJunos OS Evolved:\n\n * desde 23.2R2-S1 antes de 23.2R2-S5-EVO,\n * desde 23.4R2 antes de 23.4R2-S6-EVO,\n * desde 24.2 antes de 24.2R2-S3-EVO,\n * desde 24.4 antes de 24.4R2-S1-EVO,\n * desde 25.2 antes de 25.2R1-S2-EVO, 25.2R2-EVO."}], "id": "CVE-2026-21908", "lastModified": "2026-06-17T10:19:08.070", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "HIGH", "attackVector": "ADJACENT_NETWORK", "availabilityImpact": "HIGH", "baseScore": 7.1, "baseSeverity": "HIGH", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "LOW", "scope": "UNCHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:A/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 1.2, "impactScore": 5.9, "source": "sirt@juniper.net", "type": "Secondary"}], "cvssMetricV40": [{"cvssData": {"Automatable": "NOT_DEFINED", "Recovery": "NOT_DEFINED", "Safety": "NOT_DEFINED", "attackComplexity": "LOW", "attackRequirements": "PRESENT", "attackVector": "ADJACENT", "availabilityRequirement": "NOT_DEFINED", "baseScore": 7.5, "baseSeverity": "HIGH", "confidentialityRequirement": "NOT_DEFINED", "exploitMaturity": "NOT_DEFINED", "integrityRequirement": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "privilegesRequired": "LOW", "providerUrgency": "GREEN", "subAvailabilityImpact": "LOW", "subConfidentialityImpact": "NONE", "subIntegrityImpact": "NONE", "userInteraction": "NONE", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:A/AC:L/AT:P/PR:L/UI:N/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:X/R:X/V:X/RE:M/U:Green", "version": "4.0", "vulnAvailabilityImpact": "HIGH", "vulnConfidentialityImpact": "HIGH", "vulnIntegrityImpact": "HIGH", "vulnerabilityResponseEffort": "MODERATE"}, "source": "sirt@juniper.net", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-21908", "options": [{"exploitation": "none"}, {"automatable": "no"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-01-16T04:55:55.863089Z", "version": "2.0.3"}}]}, "published": "2026-01-15T21:16:06.537", "references": [{"source": "sirt@juniper.net", "tags": ["Vendor Advisory"], "url": "https://kb.juniper.net/JSA106007"}, {"source": "sirt@juniper.net", "tags": ["Vendor Advisory"], "url": "https://supportportal.juniper.net/JSA106007"}], "sourceIdentifier": "sirt@juniper.net", "vulnStatus": "Analyzed", "weaknesses": [{"description": [{"lang": "en", "value": "CWE-416"}], "source": "sirt@juniper.net", "type": "Secondary"}]}

{}

{"analysis": {"en": {"generated_at": "2026-04-18T05:58:51.683653+00:00", "value": {"mitigation_remediation": ["Upgrade Junos OS to any of the patched releases listed in the CNA solution (e.g., 23.2R2\u2010S5 or newer).", "Upgrade Junos OS Evolved to the corresponding patched release (e.g., 23.2R2\u2010S5\u2011EVO or newer).", "If an upgrade is not immediately possible, disable 802.1X port\u2011based network access control or otherwise prevent port flapping to reduce the risk exposure."], "summary": {"action": "Patch Immediately", "impact": "Denial of Service or potential root-level code execution"}, "threat_synthesis": {"affected_systems": "The vulnerability affects Juniper Networks Junos OS and Junos OS Evolved systems that have 802.1X port\u2011based network access control enabled. In Junos OS, all releases from 23.2R2-S1 up through 25.2R1-S2 (and earlier revisions) are vulnerable. In Junos OS Evolved, the vulnerable range extends from 23.2R2-S1 through 25.2R2-EVO.", "description_and_impact": "A use\u2011after\u2011free flaw exists in the dot1xd daemon that handles 802.1X authorization changes. When an authenticated, network\u2011adjacent attacker triggers a port flop while the daemon processes a change of authorization request, a freed pointer may be referenced again, causing dot1xd to crash. If the attacker controls the process context, the flaw could also allow arbitrary code execution as root.", "risk_and_exploitability": "The CVSS score of 7.5 indicates a high severity, but EPSS is less than 1 percent, suggesting exploitation is unlikely at the current time. The flaw was not listed in CISA\u2019s KEV catalog, but the attack requires authenticated, adjacent access and precise timing of port flapping. Successful exploitation would crash the daemon, leading to a denial of service, or, if conditions allow, execute code in the root context, which would be catastrophic for the device."}}}}, "created": "2026-01-16T13:43:01.560281+00:00", "updated": "2026-04-18T06:00:08.508708+00:00", "vendors": ["juniper_networks", "juniper_networks$PRODUCT$junos_os", "juniper_networks$PRODUCT$junos_os_evolved"]}