CVE-2026-21911

HIGH EPSS 13.1%
Published Jan 15, 20265mo ago · Modified Jun 17, 20262w ago
7.1 CVSS 4.0
High
Find Similar
Published Jan 15, 2026 5mo ago
Last Modified Jun 17, 2026 2w ago

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.

CVSS Details

Base Score
7.1
Exploitability
Impact
Vector string
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/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:C/RE:M/U:Amber
Attack Vector Adjacent
Attack Complexity Low
Privileges Required None
User Interaction None
Scope X

Threat Intelligence

EPSS Exploit Probability
13.1% percentile
Exploit & Patch Status
No Known Exploit
No Patch Available

Weaknesses 1

CWE-682

Affected Products 54

VendorProductVersionRange
juniperjunos_os_evolved* <21.4
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved21.4any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.2any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.3any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved22.4any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.2any
juniperjunos_os_evolved23.4any
juniperjunos_os_evolved23.4any
juniperjunos_os_evolved23.4any
juniperjunos_os_evolved23.4any

References 2

Remediation

No remediation data recorded yet

Check vendor advisories and the NVD entry for patch availability.