Juniper Junos OS BGP daemon buffer overflow rated 9.8

CVE-2026-102178 is a stack-based buffer overflow in the BGP routing daemon of Juniper Junos OS and Junos OS Evolved that lets a configured flowspec peer crash the daemon or compromise the routing engine via a malformed NLRI. Juniper scores it 9.8 under CVSS 3.1 and 9.3 under CVSS 4.0, with fixes in branches up to 23.2R2-S7.7, 24.4R2-S5, 25.4R1-S3 and 26.2R1-S2.

• CVSS 3.1 score is 9.8, CVSS 4.0 score is 9.3
• Exploitation needs a configured flowspec peer and update-threading enabled
• Fixes ship in 23.2R2-S7.7, 24.4R2-S5, 25.4R1-S3 and 26.2R1-S2
• ZoomEye shows 343,960 Juniper hosts but no CVE-specific matches