High 7.5Published Jan 15, 2026

CVE-2026-21906Junos OS: SRX Series: With GRE performance acceleration enabled, receipt of a specific ICMP packet causes the PFE to crash

Updated under an hour ago (Oct 27, 2026, 3:00 AM ET)

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Exploited in the last 30 days

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. This issue affects Junos OS on the SRX Series: * all versions before 21.4R3-S12, * from 22.4 before 22.4R3-S8, * from 23.2 before 23.2R2-S5, * from 23.4 before 23.4R2-S5, * from 24.2 before 24.2R2-S3, * from 24.4 before 24.4R2-S1, * from 25.2 before 25.2R1-S1, 25.2R2.

CVSS: 7.5 HIGH (v3.1, CNA)CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): CWE-755
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: juniper
NVD analysis: Analyzed
Record last updated: Jan 16, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Juniper Networks Junos OS juniper_networks:junos_os (from the name)	before 21.4R3-S12; from 22.4 before 22.4R3-S8; from 23.2 before 23.2R2-S5; from 23.4 before 23.4R2-S5; from 24.2 before 24.2R2-S3; from 24.4 before 24.4R2-S1; from 25.2 before 25.2R1-S1, 25.2R2	CNA record
juniper junos juniper:junos	before 21.4; 21.4; 21.4; 21.4; 21.4; 21.4; 21.4; 21.4; and 60 more ranges	NVD

References

References

https://supportportal.juniper.net/JSA106005	vendor-advisory
https://www.juniper.net/documentation/us/en/software/junos/vpn-ipsec/topics/topic-map/security-powermode-ipsec-vpn.html	technical-description
https://kb.juniper.net/JSA106005	vendor-advisory

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.