An Improper Resource Locking vulnerability in the clock synchronization daemon (clksyncd) of Juniper Networks Junos OS on MX Series allows a unauthenticated, logically adjacent attacker to cause a Denial-of-Service (DoS). If a SyncE or PTP upstream node sends a malformed message to an MX device equipped with SCBE3, a false 19.44MHz alarm is generated on the master RE. This leads to persistent RE switchovers and a clksyncd process crash. This issue is outside the attacker's direct control as it's a race condition. This issue affects Junos OS on MX Series: * All versions before 23.2R2-S7.7; * 23.4 versions before 23.4R2-S8.13; * 24.2 versions before 24.2R2-S5.5; * 24.4 versions before 24.4R2-S4; * 25.2 versions before 25.2R2-S1; * 25.4 versions before 25.4R1-S2.
Published: 2026-10-14
Updated: 2026-10-15
Base Score: 4.6
Vector: CVSS2#AV:A/AC:H/Au:N/C:N/I:N/A:C
Severity: Medium
Base Score: 5.3
Vector: CVSS:3.1/AV:A/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:H
Severity: Medium
Base Score: 6
Vector: CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L
Severity: Medium
EPSS: 0.00183