Improper Input Validation in Juniper Networks Junos OS Web-Filtering Module
CVE-2026-21917

8.7HIGH

Key Information:

Vendor

Juniper Networks
Status
Junos Os
Vendor
CVE Published:
15 January 2026

Badges

👾 Exploit Exists

What is CVE-2026-21917?

An Improper Validation of Syntactic Correctness of Input vulnerability exists in the Web-Filtering module of Juniper Networks' Junos OS, specifically affecting the SRX Series. This flaw allows unauthenticated attackers to exploit the system by sending specifically crafted SSL packets, leading to a Denial-of-Service condition. Upon receiving a malformed SSL packet, the affected SRX device experiences an FPC crash followed by a restart, impacting operational reliability. This issue is present in several versions of Junos OS, notably impacting versions 23.2, 23.4, 24.2, and 24.4.

Human OS v1.0:
Ageing Is an Unpatched Zero-Day Vulnerability.

Remediate biological technical debt. Prime Ageing uses 95% high-purity SIRT6 activation to maintain genomic integrity and bolster systemic resilience.

Deploy the Patch

Affected Version(s)

Junos OS SRX Series 23.2R2-S2 < 23.2R2-S5

Junos OS SRX Series 23.4R2-S1 < 23.4R2-S5

Junos OS SRX Series 24.2 < 24.2R2-S2

References

https://supportportal.juniper.net/JSA105996
vendor-advisory
https://kb.juniper.net/JSA105996
vendor-advisory

CVSS V4

Score:
8.7
Severity:
HIGH
Confidentiality:
None
Integrity:
None
Availability:
High
Attack Vector:
Network
Attack Complexity:
Low
Attack Required:
None
Privileges Required:
Undefined
User Interaction:
None

Timeline

  • 👾

    Exploit known to exist

  • Vulnerability published

  • Vulnerability Reserved

JSON
.