CVE-2026-21918Junos OS: SRX and MX Series: When TCP packets occur in a specific sequence flowd crashes
Updated under an hour ago ()
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It affects Juniper Networks Junos OS and 1 other product. Add what you run to find out whether that includes you.
No exploitation reported and no EPSS estimate yet.
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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.
- 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-415
- 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 15, 2026
- First seen by InfoSec Signals
- Oct 9, 2026
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.