Vulnerability Database

320,453

Total vulnerabilities in the database

CVE-2026-21917

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).

If an SRX device configured for UTM Web-Filtering receives a specifically malformed SSL packet, this will cause an FPC crash and restart. This issue affects Junos OS on SRX Series:

  • 23.2 versions from 23.2R2-S2 before 23.2R2-S5, 
  • 23.4 versions from 23.4R2-S1 before 23.4R2-S5,
  • 24.2 versions before 24.2R2-S2,
  • 24.4 versions before 24.4R1-S3, 24.4R2.

Earlier versions of Junos are also affected, but no fix is available.

  • Published: Jan 15, 2026
  • Updated: Jan 16, 2026
  • CVE: CVE-2026-21917
  • Severity: High
  • Exploit:

CVSS v3:

  • Severity: High
  • Score: 7.5
  • AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

CWEs:

Software From Fixed in
juniper / junos 23.2-r2-s2 23.2-r2-s2.x
juniper / junos 23.2-r2-s3 23.2-r2-s3.x
juniper / junos 23.2-r2-s4 23.2-r2-s4.x
juniper / junos 23.4-r2-s1 23.4-r2-s1.x
juniper / junos 23.4-r2-s2 23.4-r2-s2.x
juniper / junos 23.4-r2-s3 23.4-r2-s3.x
juniper / junos 23.4-r2-s4 23.4-r2-s4.x
juniper / junos 24.2 24.2.x
juniper / junos 24.2-r1 24.2-r1.x
juniper / junos 24.2-r1-s1 24.2-r1-s1.x
juniper / junos 24.2-r1-s2 24.2-r1-s2.x
juniper / junos 24.2-r2 24.2-r2.x
juniper / junos 24.2-r2-s1 24.2-r2-s1.x
juniper / junos 24.4 24.4.x
juniper / junos 24.4-r1 24.4-r1.x
juniper / junos 24.4-r1-s2 24.4-r1-s2.x
juniper / junos 24.4-r2 24.4-r2.x