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.
References
| Link | Resource |
|---|---|
| https://kb.juniper.net/JSA106020 | Vendor Advisory |
| https://supportportal.juniper.net/JSA106020 | Vendor Advisory |
Configurations
Configuration 1 (hide)
| AND |
|
History
23 Jan 2026, 18:51
| Type | Values Removed | Values Added |
|---|---|---|
| First Time |
Juniper srx5600
Juniper srx1500 Juniper Juniper srx320 Juniper srx1600 Juniper srx5400 Juniper junos Juniper srx2300 Juniper srx380 Juniper srx4120 Juniper srx5800 Juniper srx300 Juniper srx4300 Juniper srx345 Juniper srx4200 Juniper srx340 Juniper srx4100 Juniper srx4700 Juniper srx4600 |
|
| References | () https://kb.juniper.net/JSA106020 - Vendor Advisory | |
| References | () https://supportportal.juniper.net/JSA106020 - Vendor Advisory | |
| CPE | cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:* cpe:2.3:h:juniper:srx5600:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:r1:*:*:*:*:*:* cpe:2.3:h:juniper:srx380:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:r1-s2:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2-s4:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:* cpe:2.3:h:juniper:srx1500:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx1600:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:* cpe:2.3:h:juniper:srx5800:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:r1-s3:*:*:*:*:*:* cpe:2.3:h:juniper:srx4300:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx5400:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r1-s2:*:*:*:*:*:* cpe:2.3:h:juniper:srx2300:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:* cpe:2.3:h:juniper:srx340:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx345:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4600:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4700:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.4:-:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:* cpe:2.3:h:juniper:srx300:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4120:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:* cpe:2.3:h:juniper:srx320:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:* cpe:2.3:h:juniper:srx4200:-:*:*:*:*:*:*:* cpe:2.3:h:juniper:srx4100:-:*:*:*:*:*:*:* cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:* |
15 Jan 2026, 21:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-01-15 21:16
Updated : 2026-01-23 18:51
NVD link : CVE-2026-21920
Mitre link : CVE-2026-21920
CVE.ORG link : CVE-2026-21920
JSON object : View
Products Affected
juniper
- srx4120
- srx2300
- srx5600
- srx5400
- srx340
- srx4100
- srx5800
- srx4300
- srx380
- srx320
- srx1600
- srx345
- srx4200
- srx4700
- junos
- srx1500
- srx4600
- srx300
CWE
CWE-252
Unchecked Return Value