CVE-2026-21920
Severity
8.7HIGH
EPSS
0.0%
top 95.60%
CISA KEV
Not in KEV
Exploit
No known exploits
Affected products
Timeline
PublishedJan 15
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-S…
CVSS vector
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
Affected Packages2 packages
🔴Vulnerability Details
2CVEList▶
Junos OS: SRX Series: If a specific request is processed by the DNS subsystem flowd will crash↗2026-01-15
GHSA▶
GHSA-vj9c-h3r9-jwrf: An Unchecked Return Value vulnerability in the DNS module of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker↗2026-01-15
📋Vendor Advisories
1Juniper▶
CVE-2026-21920: An Unchecked Return Value vulnerability in the DNS module of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker↗2026-01-15