CVE-2026-21918
Description
A Double Free vulnerability in the flow processing daemon (flowd) of Juniper Networks Junos OS on SRX and MX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). On all SRX and MX Series platforms, when during TCP session establishment a specific sequence of packets is encountered a double free happens. This causes flowd to crash and the respective FPC to restart. This issue affects Junos OS on SRX and MX Series: * all versions before 22.4R3-S7, * 23.2 versions before 23.2R2-S3, * 23.4 versions before 23.4R2-S4, * 24.2 versions before 24.2R2.
How to fix
- juniper junos22.4 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| juniper junos | v < 22.4, 22.4, 23.2, 23.4, 24.2 | 22.4 |
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