CVE-2026-21918 (GCVE-0-2026-21918)

Vulnerability from cvelistv5 – Published: 2026-01-15 20:27 – Updated: 2026-01-15 21:13
VLAI
Title
Junos OS: SRX and MX Series: When TCP packets occur in a specific sequence flowd crashes
Summary
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.
Severity
7.5 (High)
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
8.7 (High)
CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/R:A/RE:M
SSVC
Exploitation: none Automatable: yes Technical Impact: partial
CISA Coordinator · CISA-ADP (v2.0.3)
Decision recorded 2026-01-15 21:12 UTC
CWE
Assigner
juniper CNA under the mitre root
CNA scorecard B 84/100 over 193 records in the last 180 days details
References
Impacted products
Vendor Product Version CPE status
Juniper Networks Junos OS Affected: 0 , < 22.4R3-S7 (semver)
Affected: 23.2 , < 23.2R2-S3 (semver)
Affected: 23.4 , < 23.4R2-S4 (semver)
Affected: 24.2 , < 24.2R2 (semver)
guessed Create a notification for this product.
Date Public
2026-01-14 17:00
Show details on NVD website
To clipboard 

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