CVE Vulnerabilities

CVE-2026-21918

Double Free

Published: Jan 15, 2026 | Modified: Jan 23, 2026
CVSS 3.x
N/A
Source:
NVD
CVSS 2.x
RedHat/V2
RedHat/V3
Ubuntu
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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.

Weakness

The product calls free() twice on the same memory address.

Affected Software

NameVendorStart VersionEnd Version
JunosJuniper*22.4 (excluding)
JunosJuniper22.4 (including)22.4 (including)
JunosJuniper22.4-r1 (including)22.4-r1 (including)
JunosJuniper22.4-r1-s1 (including)22.4-r1-s1 (including)
JunosJuniper22.4-r1-s2 (including)22.4-r1-s2 (including)
JunosJuniper22.4-r2 (including)22.4-r2 (including)
JunosJuniper22.4-r2-s1 (including)22.4-r2-s1 (including)
JunosJuniper22.4-r2-s2 (including)22.4-r2-s2 (including)
JunosJuniper22.4-r3 (including)22.4-r3 (including)
JunosJuniper22.4-r3-s1 (including)22.4-r3-s1 (including)
JunosJuniper22.4-r3-s2 (including)22.4-r3-s2 (including)
JunosJuniper22.4-r3-s3 (including)22.4-r3-s3 (including)
JunosJuniper22.4-r3-s4 (including)22.4-r3-s4 (including)
JunosJuniper22.4-r3-s5 (including)22.4-r3-s5 (including)
JunosJuniper22.4-r3-s6 (including)22.4-r3-s6 (including)
JunosJuniper23.2 (including)23.2 (including)
JunosJuniper23.2-r1 (including)23.2-r1 (including)
JunosJuniper23.2-r1-s1 (including)23.2-r1-s1 (including)
JunosJuniper23.2-r1-s2 (including)23.2-r1-s2 (including)
JunosJuniper23.2-r2 (including)23.2-r2 (including)
JunosJuniper23.2-r2-s1 (including)23.2-r2-s1 (including)
JunosJuniper23.2-r2-s2 (including)23.2-r2-s2 (including)
JunosJuniper23.4 (including)23.4 (including)
JunosJuniper23.4-r1 (including)23.4-r1 (including)
JunosJuniper23.4-r1-s1 (including)23.4-r1-s1 (including)
JunosJuniper23.4-r1-s2 (including)23.4-r1-s2 (including)
JunosJuniper23.4-r2 (including)23.4-r2 (including)
JunosJuniper23.4-r2-s1 (including)23.4-r2-s1 (including)
JunosJuniper23.4-r2-s2 (including)23.4-r2-s2 (including)
JunosJuniper23.4-r2-s3 (including)23.4-r2-s3 (including)
JunosJuniper24.2 (including)24.2 (including)
JunosJuniper24.2-r1 (including)24.2-r1 (including)
JunosJuniper24.2-r1-s1 (including)24.2-r1-s1 (including)
JunosJuniper24.2-r1-s2 (including)24.2-r1-s2 (including)

Potential Mitigations

References