CVE-2026-21917
Unknown
Unknown - Not Provided
BaseFortify
Vulnerability report for CVE-2026-21917, including description, CVSS score, EPSS score, affected products, exploitability, helpful resources, and attack-flow context.
Publication date: 2026-01-15
Last updated on: 2026-01-15
Assigner: Juniper Networks, Inc.
Description
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).
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.
CVSS Scores
EPSS Scores
| Probability: | |
| Percentile: |
Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| juniper_networks | junos_os | From 23.2R2-S2 (inc) to 23.2R2-S5 (exc) |
| juniper_networks | junos_os | From 23.4R2-S1 (inc) to 23.4R2-S5 (exc) |
| juniper_networks | junos_os | to 24.2R2-S2 (exc) |
| juniper_networks | junos_os | to 24.4R1-S3 (exc) |
Helpful Resources
Exploitability
CWE
KEV
| CWE ID | Description |
|---|---|
| CWE-1286 | The product receives input that is expected to be well-formed - i.e., to comply with a certain syntax - but it does not validate or incorrectly validates that the input complies with the syntax. |
