CVE-2026-21914
Severity CVSS v4.0:
HIGH
Type:
Unavailable / Other
Publication date:
15/01/2026
Last modified:
15/01/2026
Description
An Improper Locking vulnerability in the GTP plugin of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (Dos).<br />
<br />
If an SRX Series device receives a specifically malformed GPRS Tunnelling Protocol (GTP) Modify Bearer Request message, a lock is acquired and never released. This results in other threads not being able to acquire a lock themselves, causing a watchdog timeout leading to FPC crash and restart. This issue leads to a complete traffic outage until the device has automatically recovered.<br />
<br />
This issue affects Junos OS on SRX Series:<br />
<br />
* all versions before 22.4R3-S8,<br />
* 23.2 versions before 23.2R2-S5,<br />
* 23.4 versions before 23.4R2-S6,<br />
* 24.2 versions before 24.2R2-S3,<br />
* 24.4 versions before 24.4R2-S2,<br />
* 25.2 versions before 25.2R1-S1, 25.2R2.
Impact
Base Score 4.0
8.70
Severity 4.0
HIGH
Base Score 3.x
7.50
Severity 3.x
HIGH