vulnerability
Juniper Junos OS: 2026-01 Security Bulletin: Junos OS: SRX Series: With GRE performance acceleration enabled, receipt of a specific ICMP packet causes the PFE to crash (JSA106005) (CVE-2026-21906)
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 8 | (AV:N/AC:L/Au:N/C:N/I:N/A:C) | Jan 14, 2026 | Jan 27, 2026 | Jan 27, 2026 |
Description
An Improper Handling of Exceptional Conditions vulnerability in the packet forwarding engine (PFE) of Juniper Networks Junos OS on SRX Series allows an unauthenticated network-based attacker sending a specific ICMP packet through a GRE tunnel to cause the PFE to crash and restart.When PowerMode IPsec (PMI) and GRE performance acceleration are enabled and the device receives a specific ICMP packet, a crash occurs in the SRX PFE, resulting in traffic loss. PMI is enabled by default, and GRE performance acceleration can be enabled by running the configuration command shown below. PMI is a mode of operation that provides IPsec performance improvements using Vector Packet Processing.Note that PMI with GRE performance acceleration is only supported on specific SRX platforms.
Solution
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