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TI-2026-17618 Aliases CVE-2026-21918GHSA-9m47-29xf-m969

Junos OS: SRX and MX Series: When TCP packets occur in a specific sequence flowd crashes

Priority MEDIUM 44CWE-415Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
Low
Attack requirements
None
Impact type
Denial of service
Confidentiality · integrity · availability
None · None · High
Fix status
Fixed

Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-415 and the CVSS impact.

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.

Why it matters now

Exploitation None reported CISA SSVC · not in CISA KEV
EPSS 0.00407 35th percentileScored 2026-11-07
Fix Fixed Junos OS (Juniper Networks): 22.4R3-S7, 23.2R2-S3, 23.4R2-S4 +1

SSVC decision points

CISA ADP · SSVC 2.0.3

Exploitation
None
Automatable
Yes
Technical impact
Partial

The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.

Affected products

VendorProductAffected versionsFixed inStatusSource
JuniperJunos OSbefore 22.4R3-S7; 23.2 to before 23.2R2-S3; 23.4 to before 23.4R2-S4; 24.2 to before 24.2R222.4R3-S7, 23.2R2-S3, 23.4R2-S4, 24.2R2Patch availableCNA
  • Junos OS VendorJuniper Affected before 22.4R3-S7; 23.2 to before 23.2R2-S3; 23.4 to before 23.4R2-S4; 24.2 to before 24.2R2 Fixed in 22.4R3-S7, 23.2R2-S3, 23.4R2-S4, 24.2R2 Patch available CNA

CPE configurations NVD · 61

CPEVersionsRoleVendor
cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:*before 22.4VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:*22.4VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:*22.4 r1VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:*22.4 r1-s1VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:*22.4 r1-s2VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:*22.4 r2VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:*22.4 r2-s1VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r2-s2:*:*:*:*:*:*22.4 r2-s2VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:*22.4 r3VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r3-s1:*:*:*:*:*:*22.4 r3-s1VulnerableJuniper
  • cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* Versions before 22.4 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:-:*:*:*:*:*:* Versions 22.4 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r1:*:*:*:*:*:* Versions 22.4 r1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r1-s1:*:*:*:*:*:* Versions 22.4 r1-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r1-s2:*:*:*:*:*:* Versions 22.4 r1-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r2:*:*:*:*:*:* Versions 22.4 r2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r2-s1:*:*:*:*:*:* Versions 22.4 r2-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r2-s2:*:*:*:*:*:* Versions 22.4 r2-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r3:*:*:*:*:*:* Versions 22.4 r3 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r3-s1:*:*:*:*:*:* Versions 22.4 r3-s1 Vulnerable ·Juniper
Show 51 more CPE
CPEVersionsRoleVendor
cpe:2.3:o:juniper:junos:22.4:r3-s2:*:*:*:*:*:*22.4 r3-s2VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r3-s3:*:*:*:*:*:*22.4 r3-s3VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r3-s4:*:*:*:*:*:*22.4 r3-s4VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r3-s5:*:*:*:*:*:*22.4 r3-s5VulnerableJuniper
cpe:2.3:o:juniper:junos:22.4:r3-s6:*:*:*:*:*:*22.4 r3-s6VulnerableJuniper
cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:*23.2VulnerableJuniper
cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:*23.2 r1VulnerableJuniper
cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:*23.2 r1-s1VulnerableJuniper
cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:*23.2 r1-s2VulnerableJuniper
cpe:2.3:o:juniper:junos:23.2:r2:*:*:*:*:*:*23.2 r2VulnerableJuniper
cpe:2.3:o:juniper:junos:23.2:r2-s1:*:*:*:*:*:*23.2 r2-s1VulnerableJuniper
cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:*23.2 r2-s2VulnerableJuniper
cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:*23.4VulnerableJuniper
cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:*23.4 r1VulnerableJuniper
cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:*23.4 r1-s1VulnerableJuniper
cpe:2.3:o:juniper:junos:23.4:r1-s2:*:*:*:*:*:*23.4 r1-s2VulnerableJuniper
cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:*23.4 r2VulnerableJuniper
cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:*23.4 r2-s1VulnerableJuniper
cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:*23.4 r2-s2VulnerableJuniper
cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:*23.4 r2-s3VulnerableJuniper
cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:*24.2VulnerableJuniper
cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:*24.2 r1VulnerableJuniper
cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:*24.2 r1-s1VulnerableJuniper
cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:*24.2 r1-s2VulnerableJuniper
cpe:2.3:h:juniper:mx10004:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx10008:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx2008:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx2010:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx2020:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx204:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx240:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx304:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx480:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:mx960:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx1500:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx1600:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx2300:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx300:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx320:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx340:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx345:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx380:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx4100:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx4120:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx4200:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx4300:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx4600:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx4700:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx5400:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx5600:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
cpe:2.3:h:juniper:srx5800:-:*:*:*:*:*:*:*not specified by NVDRunning onJuniper
  • cpe:2.3:o:juniper:junos:22.4:r3-s2:*:*:*:*:*:* Versions 22.4 r3-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r3-s3:*:*:*:*:*:* Versions 22.4 r3-s3 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r3-s4:*:*:*:*:*:* Versions 22.4 r3-s4 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r3-s5:*:*:*:*:*:* Versions 22.4 r3-s5 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:22.4:r3-s6:*:*:*:*:*:* Versions 22.4 r3-s6 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:* Versions 23.2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:* Versions 23.2 r1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:* Versions 23.2 r1-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:* Versions 23.2 r1-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.2:r2:*:*:*:*:*:* Versions 23.2 r2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.2:r2-s1:*:*:*:*:*:* Versions 23.2 r2-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:* Versions 23.2 r2-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:* Versions 23.4 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:* Versions 23.4 r1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:* Versions 23.4 r1-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.4:r1-s2:*:*:*:*:*:* Versions 23.4 r1-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:* Versions 23.4 r2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:* Versions 23.4 r2-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:* Versions 23.4 r2-s2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:* Versions 23.4 r2-s3 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:* Versions 24.2 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:* Versions 24.2 r1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:* Versions 24.2 r1-s1 Vulnerable ·Juniper
  • cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:* Versions 24.2 r1-s2 Vulnerable ·Juniper
  • cpe:2.3:h:juniper:mx10004:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx10008:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx2008:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx2010:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx2020:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx204:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx240:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx304:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx480:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:mx960:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx1500:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx1600:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx2300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx320:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx340:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx345:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx380:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx4100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx4120:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx4200:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx4300:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx4600:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx4700:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx5400:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx5600:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
  • cpe:2.3:h:juniper:srx5800:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper

Remediation

  • Fix · CNA Junos OS (Juniper Networks) Fixed in 22.4R3-S7, 23.2R2-S3, 23.4R2-S4, 24.2R2

Timeline

  1. 2026-10-02 Threatist record created from CVE-2026-21918
  2. 2026-10-03 Alias added: GHSA-9m47-29xf-m969

References

Advisory 2

  • TI-2023-18638 Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to… KEVCVSS 3.1CRITICAL 9.8
  • TI-2020-01585 Out of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) services KEVCVSS 3.1CRITICAL 9.8
  • TI-2015-04610 Assertion failure in ISC BIND named via TKEY queries KEVCVSS 3.1HIGH 7.5
  • TI-2025-15550 Junos OS: An local attacker with shell access can execute arbitrary code KEVCVSS 4.0MEDIUM 6.7
  • TI-2023-18644 Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload and download arbitrary files KEVCVSS 3.1MEDIUM 5.3
  • TI-2023-18640 Junos OS: EX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary files KEVCVSS 3.1MEDIUM 5.3
See all 792 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences