CVE-2026-21921

{"id": "CVE-2026-21921", "cveTags": [], "metrics": {"cvssMetricV31": [{"type": "Primary", "source": "[email protected]", "cvssData": {"scope": "UNCHANGED", "version": "3.1", "baseScore": 6.5, "attackVector": "NETWORK", "baseSeverity": "MEDIUM", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H", "integrityImpact": "NONE", "userInteraction": "NONE", "attackComplexity": "LOW", "availabilityImpact": "HIGH", "privilegesRequired": "LOW", "confidentialityImpact": "NONE"}, "impactScore": 3.6, "exploitabilityScore": 2.8}], "cvssMetricV40": [{"type": "Secondary", "source": "[email protected]", "cvssData": {"Safety": "NOT_DEFINED", "version": "4.0", "Recovery": "AUTOMATIC", "baseScore": 7.1, "Automatable": "YES", "attackVector": "NETWORK", "baseSeverity": "HIGH", "valueDensity": "NOT_DEFINED", "vectorString": "CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/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:A/V:X/RE:M/U:X", "exploitMaturity": "NOT_DEFINED", "providerUrgency": "NOT_DEFINED", "userInteraction": "NONE", "attackComplexity": "LOW", "attackRequirements": "NONE", "privilegesRequired": "LOW", "subIntegrityImpact": "NONE", "vulnIntegrityImpact": "NONE", "integrityRequirement": "NOT_DEFINED", "modifiedAttackVector": "NOT_DEFINED", "subAvailabilityImpact": "LOW", "vulnAvailabilityImpact": "HIGH", "availabilityRequirement": "NOT_DEFINED", "modifiedUserInteraction": "NOT_DEFINED", "modifiedAttackComplexity": "NOT_DEFINED", "subConfidentialityImpact": "NONE", "vulnConfidentialityImpact": "NONE", "confidentialityRequirement": "NOT_DEFINED", "modifiedAttackRequirements": "NOT_DEFINED", "modifiedPrivilegesRequired": "NOT_DEFINED", "modifiedSubIntegrityImpact": "NOT_DEFINED", "modifiedVulnIntegrityImpact": "NOT_DEFINED", "vulnerabilityResponseEffort": "MODERATE", "modifiedSubAvailabilityImpact": "NOT_DEFINED", "modifiedVulnAvailabilityImpact": "NOT_DEFINED", "modifiedSubConfidentialityImpact": "NOT_DEFINED", "modifiedVulnConfidentialityImpact": "NOT_DEFINED"}}]}, "published": "2026-01-15T21:16:08.400", "references": [{"url": "https://kb.juniper.net/JSA106021", "tags": ["Vendor Advisory"], "source": "[email protected]"}, {"url": "https://supportportal.juniper.net/JSA106021", "tags": ["Vendor Advisory"], "source": "[email protected]"}], "vulnStatus": "Analyzed", "weaknesses": [{"type": "Primary", "source": "[email protected]", "description": [{"lang": "en", "value": "CWE-416"}]}], "descriptions": [{"lang": "en", "value": "A Use After Free vulnerability in the chassis daemon (chassisd) of Juniper Networks Junos OS and Junos OS Evolved allows a network-based attacker authenticated with low privileges to cause a Denial-of-Service (DoS).\n\nWhen telemetry collectors are frequently subscribing and unsubscribing to sensors continuously over a long period of time, telemetry-capable processes like chassisd, rpd or mib2d will crash and restart, which - depending on the process - can cause a complete outage until the system has recovered.\n\nThis issue affects:\n\n\u00a0Junos OS:\u00a0\n\n\n\n * all versions before 22.4R3-S8,\n * 23.2 versions before 23.2R2-S5,\n * 23.4 versions before 23.4R2;\n\n\n\n\nJunos OS Evolved:\n\n\n\n * all versions before 22.4R3-S8-EVO,\n * 23.2 versions before 23.2R2-S5-EVO,\n * 23.4 versions before 23.4R2-EVO."}], "lastModified": "2026-01-23T18:52:35.070", "configurations": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "57F66641-003B-49D6-A9B9-AB300CFE3C93", "versionEndExcluding": "22.4"}, {"criteria": "cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "1379EF30-AF04-4F98-8328-52A631F24737"}, {"criteria": "cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:*", "vulnerable": true, "matchCriteriaId": "28E42A41-7965-456B-B0AF-9D3229CE4D4C"}, {"criteria": "cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:*", "vulnerable": true, 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