CVE-2026-21917
Severity CVSS v4.0:
HIGH
Type:
Unavailable / Other
Publication date:
15/01/2026
Last modified:
15/01/2026
Description
An Improper Validation of Syntactic Correctness of Input vulnerability in the Web-Filtering module of Juniper Networks Junos OS on SRX Series allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS).<br />
<br />
If an SRX device configured for UTM Web-Filtering receives a specifically malformed SSL packet, this will cause an FPC crash and restart.<br />
This issue affects Junos OS on SRX Series:<br />
<br />
<br />
<br />
* 23.2 versions from 23.2R2-S2 before 23.2R2-S5, <br />
* 23.4 versions from 23.4R2-S1 before 23.4R2-S5,<br />
* 24.2 versions before 24.2R2-S2,<br />
* 24.4 versions before 24.4R1-S3, 24.4R2.<br />
<br />
<br />
Earlier versions of Junos are also affected, but no fix is available.
Impact
Base Score 4.0
8.70
Severity 4.0
HIGH
Base Score 3.x
7.50
Severity 3.x
HIGH