An Incorrect Calculation vulnerability in the Layer 2 Control
Protocol
Daemon (l2cpd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-adjacent attacker flapping the management interface to cause the learning of new MACs over label-switched interfaces (LSI) to stop while generating a flood of logs, resulting in high CPU usage.
When the issue is seen, the following log message will be generated:
op:1 flag:0x6 mac:xx:xx:xx:xx:xx:xx bd:2 ifl:13302 reason:0(REASON_NONE) i-op:6(INTRNL_OP_HW_FORCE_DELETE) status:10 lstatus:10 err:26(GETIFBD_VALIDATE_FAILED) err-reason 4(IFBD_VALIDATE_FAIL_EPOCH_MISMATCH) hw_wr:0x4 ctxsync:0 fwdsync:0 rtt-id:51 p_ifl:0 fwd_nh:0 svlbnh:0 event:- smask:0x100000000 dmask:0x0 mplsmask 0x1 act:0x5800 extf:0x0 pfe-id 0 hw-notif-ifl 13302 programmed-ifl 4294967295 pseudo-vtep underlay-ifl-idx 0 stack:GET_MAC, ALLOCATE_MAC, GET_IFL, GET_IFF, GET_IFBD, STOP,
This issue affects Junos OS Evolved:
* all versions before 21.4R3-S7-EVO,
* from 22.2 before 22.2R3-S4-EVO,
* from 22.3 before 22.3R3-S3-EVO,
* from 22.4 before 22.4R3-S2-EVO,
* from 23.2 before 23.2R2-S1-EVO,
* from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO.
Metrics
Affected Vendors & Products
References
History
Thu, 15 Jan 2026 21:15:00 +0000
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ssvc
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Thu, 15 Jan 2026 20:30:00 +0000
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| Description | An Incorrect Calculation vulnerability in the Layer 2 Control Protocol Daemon (l2cpd) of Juniper Networks Junos OS Evolved allows an unauthenticated network-adjacent attacker flapping the management interface to cause the learning of new MACs over label-switched interfaces (LSI) to stop while generating a flood of logs, resulting in high CPU usage. When the issue is seen, the following log message will be generated: op:1 flag:0x6 mac:xx:xx:xx:xx:xx:xx bd:2 ifl:13302 reason:0(REASON_NONE) i-op:6(INTRNL_OP_HW_FORCE_DELETE) status:10 lstatus:10 err:26(GETIFBD_VALIDATE_FAILED) err-reason 4(IFBD_VALIDATE_FAIL_EPOCH_MISMATCH) hw_wr:0x4 ctxsync:0 fwdsync:0 rtt-id:51 p_ifl:0 fwd_nh:0 svlbnh:0 event:- smask:0x100000000 dmask:0x0 mplsmask 0x1 act:0x5800 extf:0x0 pfe-id 0 hw-notif-ifl 13302 programmed-ifl 4294967295 pseudo-vtep underlay-ifl-idx 0 stack:GET_MAC, ALLOCATE_MAC, GET_IFL, GET_IFF, GET_IFBD, STOP, This issue affects Junos OS Evolved: * all versions before 21.4R3-S7-EVO, * from 22.2 before 22.2R3-S4-EVO, * from 22.3 before 22.3R3-S3-EVO, * from 22.4 before 22.4R3-S2-EVO, * from 23.2 before 23.2R2-S1-EVO, * from 23.4 before 23.4R1-S2-EVO, 23.4R2-EVO. | |
| Title | Junos OS Evolved: Flapping management interface causes MAC learning on label-switched interfaces to stop | |
| Weaknesses | CWE-682 | |
| References |
| |
| Metrics |
cvssV3_1
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Status: PUBLISHED
Assigner: juniper
Published:
Updated: 2026-01-15T20:51:32.531Z
Reserved: 2026-01-05T17:32:48.710Z
Link: CVE-2026-21911
Updated: 2026-01-15T20:51:29.799Z
Status : Received
Published: 2026-01-15T21:16:07.110
Modified: 2026-01-15T21:16:07.110
Link: CVE-2026-21911
No data.
OpenCVE Enrichment
No data.