Daemon crash via ESI-route memory leak
Published Apr 9, 2026 · Updated Apr 9, 2026
Memory leak in l2ald in Juniper Networks Junos OS and Junos OS Evolved allows adjacent attackers to crash and restart the daemon. In EVPN-MPLS deployments, l2ald fails to release memory allocated for ESI routes learned from remote multihomed provider-edge devices when those routes churn. No authentication or user interaction is required, but the attacker must be adjacent and able to induce ESI-route churn; exhaustion interrupts Layer 2 address learning until l2ald restarts.
Summary
What happened
Memory leak in l2ald in Juniper Networks Junos OS and Junos OS Evolved allows adjacent attackers to crash and restart the daemon. In EVPN-MPLS deployments, l2ald fails to release memory allocated for ESI routes learned from remote multihomed provider-edge devices when those routes churn. No authentication or user interaction is required, but the attacker must be adjacent and able to induce ESI-route churn; exhaustion interrupts Layer 2 address learning until l2ald restarts.
The record
- CVE
- CVE-2026-33780
- Published
- Apr 9, 2026
- Updated
- Apr 9, 2026
- Vendor
- Juniper Networks
- Product
- Junos OS Evolved
- Classifications
- CWE-401, T1499.004
- Attack vector
- adjacent
- Privileges
- unauthenticated
Timeline
How it unfolded
- Apr 9, 2026CVE publishedPublication date reported by the CVE source.
- Apr 9, 2026Record updatedLatest update available in the CVE record.
Exploitability
Present is not the same as exploitable
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Is a vulnerable build present?
Compare these published version ranges with your installed build and any vendor patches.
- Affected versionversion=23.2 <23.2R2-S3-EVO
- Affected versionversion=23.4 <23.4R2-S4-EVO
- Affected versionversion=24.2 <24.2R2-EVO
- Affected versionversion=all version prior to <22.4R3-S5-EVO
What conditions does exploitation require?
What is affected?
Published CVSS scores
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Attacks
What attackers are doing with it
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Weakness, pattern, technique
Public exploit references
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Technologies
Your stack
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Your stack
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