CVE Catalog

CVE-2026-21914

High
Published: Translated: NVD NIST

Summary

The GTP plugin in Junos OS on SRX Series contains an Improper Locking vulnerability. An unauthenticated network-based attacker can send a specially crafted GTP Modify Bearer Request message, causing a lock to be acquired and never released, leading to a watchdog timeout and FPC crash and restart.

Risk Assessment

The attack can cause a complete traffic outage until the device automatically recovers, impacting service availability and business continuity.

Recommendation

Immediately upgrade Junos OS to a patched version as listed in the CVE description. Additionally, restrict access to GTP interfaces to trusted sources only.

Related vulnerabilities

Original NVD description (English source)

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). 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. This issue affects Junos OS on SRX Series: * all versions before 22.4R3-S8, * 23.2 versions before 23.2R2-S5, * 23.4 versions before 23.4R2-S6, * 24.2 versions before 24.2R2-S3, * 24.4 versions before 24.4R2-S2, * 25.2 versions before 25.2R1-S1, 25.2R2.

Vulnerability data from NVD (NIST) · CISA KEV · EPSS