{"id":"CVE-2026-33780","state":"PUBLISHED","title":"Junos OS and Junos OS Evolved: In an EVPN-MPLS scenario churn of ESI routes causes a memory leak in l2ald","description":"A Missing Release of Memory after Effective Lifetime vulnerability in the Layer 2 Address Learning Daemon (l2ald) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause a memory leak ultimately leading to a Denial of Service (DoS).\n\n\n\nIn an EVPN-MPLS scenario, routes learned from remote multi-homed Provider Edge (PE) devices are programmed as ESI routes. Due to a logic issue in the l2ald memory management, memory allocated for these routes is not released when there is churn for these routes. As a result, memory leaks in the l2ald process which will ultimately lead to a crash and restart of l2ald.\n\nUse the following command to monitor the memory consumption by l2ald:\n\nuser@device> show system process extensive | match \"PID|l2ald\" \n\n\n\nThis issue affects:\n\nJunos OS:\n\n\n\n  *  all versions before 22.4R3-S5,\n  *  23.2 versions before 23.2R2-S3,\n  *  23.4 versions before 23.4R2-S4,\n  *  24.2 versions before 24.2R2;\n\n\n\n\nJunos OS Evolved:\n\n\n\n  *  all versions before 22.4R3-S5-EVO,\n  *  23.2 versions before 23.2R2-S3-EVO,\n  *  23.4 versions before 23.4R2-S4-EVO,\n  *  24.2 versions before 24.2R2-EVO.","publishedAt":"2026-04-09T21:29:20.534Z","updatedAt":"2026-04-13T18:06:19.950Z","severity":{"score":7.1,"label":"High","version":"4.0","vector":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/RE:M","source":"juniper"},"assigner":"juniper","products":["Juniper Networks Junos OS","Juniper Networks Junos OS Evolved"],"affected":[{"vendor":"Juniper Networks","product":"Junos OS","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"22.4R3-S5","versionType":"semver"},{"version":"23.2","status":"affected","lessThan":"23.2R2-S3","versionType":"semver"},{"version":"23.4","status":"affected","lessThan":"23.4R2-S4","versionType":"semver"},{"version":"24.2","status":"affected","lessThan":"24.2R2","versionType":"semver"}]},{"vendor":"Juniper Networks","product":"Junos OS Evolved","defaultStatus":"unaffected","versions":[{"version":"all version prior to","status":"affected","lessThan":"22.4R3-S5-EVO","versionType":"semver"},{"version":"23.2","status":"affected","lessThan":"23.2R2-S3-EVO","versionType":"semver"},{"version":"23.4","status":"affected","lessThan":"23.4R2-S4-EVO","versionType":"semver"},{"version":"24.2","status":"affected","lessThan":"24.2R2-EVO","versionType":"semver"}]}],"references":["https://kb.juniper.net/JSA107819"],"weaknesses":["CWE-401"],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/33xxx/CVE-2026-33780.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-33780","state":"PUBLISHED","datePublished":"2026-04-09T21:29:20.534Z","dateUpdated":"2026-04-13T18:06:19.950Z","assignerShortName":"juniper","assignerOrgId":"8cbe9d5a-a066-4c94-8978-4b15efeae968","dateReserved":"2026-03-23T19:46:13.669Z"},"containers":{"cna":{"title":"Junos OS and Junos OS Evolved: In an EVPN-MPLS scenario churn of ESI routes causes a memory leak in l2ald","descriptions":[{"lang":"en","value":"A Missing Release of Memory after Effective Lifetime vulnerability in the Layer 2 Address Learning Daemon (l2ald) of Juniper Networks Junos OS and Junos OS Evolved allows an adjacent, unauthenticated attacker to cause a memory leak ultimately leading to a Denial of Service (DoS).\n\n\n\nIn an EVPN-MPLS scenario, routes learned from remote multi-homed Provider Edge (PE) devices are programmed as ESI routes. Due to a logic issue in the l2ald memory management, memory allocated for these routes is not released when there is churn for these routes. As a result, memory leaks in the l2ald process which will ultimately lead to a crash and restart of l2ald.\n\nUse the following command to monitor the memory consumption by l2ald:\n\nuser@device> show system process extensive | match \"PID|l2ald\" \n\n\n\nThis issue affects:\n\nJunos OS:\n\n\n\n  *  all versions before 22.4R3-S5,\n  *  23.2 versions before 23.2R2-S3,\n  *  23.4 versions before 23.4R2-S4,\n  *  24.2 versions before 24.2R2;\n\n\n\n\nJunos OS Evolved:\n\n\n\n  *  all versions before 22.4R3-S5-EVO,\n  *  23.2 versions before 23.2R2-S3-EVO,\n  *  23.4 versions before 23.4R2-S4-EVO,\n  *  24.2 versions before 24.2R2-EVO."}],"affected":[{"vendor":"Juniper Networks","product":"Junos OS","defaultStatus":"unaffected","versions":[{"version":"0","status":"affected","lessThan":"22.4R3-S5","versionType":"semver"},{"version":"23.2","status":"affected","lessThan":"23.2R2-S3","versionType":"semver"},{"version":"23.4","status":"affected","lessThan":"23.4R2-S4","versionType":"semver"},{"version":"24.2","status":"affected","lessThan":"24.2R2","versionType":"semver"}]},{"vendor":"Juniper Networks","product":"Junos OS Evolved","defaultStatus":"unaffected","versions":[{"version":"all version prior to","status":"affected","lessThan":"22.4R3-S5-EVO","versionType":"semver"},{"version":"23.2","status":"affected","lessThan":"23.2R2-S3-EVO","versionType":"semver"},{"version":"23.4","status":"affected","lessThan":"23.4R2-S4-EVO","versionType":"semver"},{"version":"24.2","status":"affected","lessThan":"24.2R2-EVO","versionType":"semver"}]}],"references":[{"url":"https://kb.juniper.net/JSA107819","tags":["vendor-advisory"]}],"metrics":[{"cvssV3_1":{"attackComplexity":"LOW","attackVector":"ADJACENT_NETWORK","availabilityImpact":"HIGH","baseScore":6.5,"baseSeverity":"MEDIUM","confidentialityImpact":"NONE","integrityImpact":"NONE","privilegesRequired":"NONE","scope":"UNCHANGED","userInteraction":"NONE","vectorString":"CVSS:3.1/AV:A/AC:L/PR:N/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":"NOT_DEFINED","Safety":"NOT_DEFINED","attackComplexity":"LOW","attackRequirements":"NONE","attackVector":"ADJACENT","baseScore":7.1,"baseSeverity":"HIGH","privilegesRequired":"NONE","providerUrgency":"NOT_DEFINED","subAvailabilityImpact":"LOW","subConfidentialityImpact":"NONE","subIntegrityImpact":"NONE","userInteraction":"NONE","valueDensity":"NOT_DEFINED","vectorString":"CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/RE:M","version":"4.0","vulnAvailabilityImpact":"HIGH","vulnConfidentialityImpact":"NONE","vulnIntegrityImpact":"NONE","vulnerabilityResponseEffort":"MODERATE"},"format":"CVSS","scenarios":[{"lang":"en","value":"GENERAL"}]}],"problemTypes":[{"descriptions":[{"cweId":"CWE-401","description":"CWE-401 Missing Release of Memory after Effective Lifetime","lang":"en","type":"CWE"}]}],"providerMetadata":{"shortName":"juniper","orgId":"8cbe9d5a-a066-4c94-8978-4b15efeae968","dateUpdated":"2026-04-09T21:29:20.534Z"},"configurations":[{"lang":"en","supportingMedia":[{"base64":false,"type":"text/html","value":"<span style=\"background-color: rgb(251, 251, 251);\">To be exposed to this issue the device must be configured for EVPN-MPLS. Refer to product documentation for how to configure EVPN-MPLS as there are different configuration options.</span>\n\n<br>"}],"value":"To be exposed to this issue the device must be configured for EVPN-MPLS. Refer to product documentation for how to configure EVPN-MPLS as there are different configuration options."}],"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: <br>Junos OS Evolved: 22.4R3-S5-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, 24.4R1-EVO,&nbsp;and all subsequent releases;<br>Junos OS: 22.4R3-S5, 23.2R2-S3, 23.4R2-S4, 24.2R2, 24.4R1, and all subsequent releases."}],"value":"The following software releases have been updated to resolve this specific issue: \nJunos OS Evolved: 22.4R3-S5-EVO, 23.2R2-S3-EVO, 23.4R2-S4-EVO, 24.2R2-EVO, 24.4R1-EVO, and all subsequent releases;\nJunos OS: 22.4R3-S5, 23.2R2-S3, 23.4R2-S4, 24.2R2, 24.4R1, and all subsequent releases."}],"source":{"advisory":"JSA107819","defect":["1824956"],"discovery":"USER"},"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":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-33780","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"version":"2.0.3","timestamp":"2026-04-13T17:39:43.706961Z"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-04-13T18:06:19.950Z"}}]}}}