Unrated severityNVD Advisory· Published Jan 15, 2026· Updated Jan 15, 2026
Junos OS: SRX Series: Specifically malformed SSL packet causes FPC crash
CVE-2026-21917
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.
Affected products
2- Range: 23.2R2-S2 to 23.2R2-S5, 23.4R2-S1 to 23.4R2-S5, 24.2 before 24.2R2-S2, 24.4 before 24.4R1-S3 or 24.4R2
- Juniper Networks/Junos OSv5Range: 23.2R2-S2
Patches
0No patches discovered yet.
Vulnerability mechanics
AI mechanics synthesis has not run for this CVE yet.
References
2- kb.juniper.net/JSA105996mitrevendor-advisory
- supportportal.juniper.net/JSA105996mitrevendor-advisory
News mentions
0No linked articles in our index yet.