VYPR
Unrated severityNVD Advisory· Published Jan 15, 2026· Updated Jan 15, 2026

Junos OS: SRX Series: If a specific request is processed by the DNS subsystem flowd will crash

CVE-2026-21920

Description

An Unchecked Return Value vulnerability in the DNS module of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).

If an SRX Series device configured for DNS processing, receives a specifically formatted DNS request flowd will crash and restart, which causes a service interruption until the process has recovered.

This issue affects Junos OS on SRX Series:

  • 23.4 versions before 23.4R2-S5,
  • 24.2 versions before 24.2R2-S1,
  • 24.4 versions before 24.4R2.

This issue does not affect Junos OS versions before 23.4R1.

Affected products

2
  • Range: >=23.4, <23.4R2-S5 or >=24.2, <24.2R2-S1 or >=24.4, <24.4R2
  • Juniper Networks/Junos OSv5
    Range: 23.4

Patches

0

No patches discovered yet.

Vulnerability mechanics

AI mechanics synthesis has not run for this CVE yet.

References

2

News mentions

0

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