CVE-2025-30646: Junos OS and Junos OS Evolved: Receipt of a malformed LLDP TLV results in l2cpd crash
A Signed to Unsigned Conversion Error vulnerability in the Layer 2 Control Protocol daemon (l2cpd) of Juniper Networks Junos OS and Juniper Networks Junos OS Evolved allows an unauthenticated adjacent attacker sending a specifically malformed LLDP TLV to cause the l2cpd process to crash and restart, causing a Denial of Service (DoS). Continued receipt and processing of this packet will create a sustained Denial of Service (DoS) condition.
When an LLDP telemetry subscription is active, receipt of a specifically malformed LLDP TLV causes the l2cpd process to crash and restart.
This issue affects:
Junos OS:
All versions before 21.2R3-S9, from 21.4 before 21.4R3-S10, from 22.2 before 22.2R3-S6, from 22.4 before 22.4R3-S6, from 23.2 before 23.2R2-S3, from 23.4 before 23.4R2-S4, from 24.2 before 24.2R2;
Junos OS Evolved:
All versions before 21.4R3-S10-EVO, from 22.2-EVO before 22.2R3-S6-EVO, from 22.4-EVO before 22.4R3-S6-EVO, from 23.2-EVO before 23.2R2-S3-EVO, from 23.4-EVO before 23.4R2-S4-EVO, from 24.2-EVO before 24.2R2-EVO.
Affected Software
Remediation
Information
Event History
Frequently Asked Questions
What is the severity of CVE-2025-30646?
CVE-2025-30646 has been classified as a high severity vulnerability.
How do I fix CVE-2025-30646?
To mitigate CVE-2025-30646, apply the security patches provided by Juniper for affected versions of Junos OS.
Who is affected by CVE-2025-30646?
CVE-2025-30646 affects Juniper Networks Junos OS versions up to 21.2R3-S9 and Junos OS Evolved versions up to 21.4R3-S10-EVO.
What does CVE-2025-30646 exploit?
CVE-2025-30646 exploits a signed to unsigned conversion error in the Layer 2 Control Protocol daemon.
What type of attack can CVE-2025-30646 facilitate?
CVE-2025-30646 allows an unauthenticated adjacent attacker to disrupt the l2cpd process by sending a specifically malformed LLDP TLV.