CVE-2026-102178
Junos OS and Junos OS Evolved: When BGP update-threading is enabled a specifically malformed flowspec NLRI causes routing-engine compromise
Juniper Networks Junos OSNetwork & edge
CVSS
9.8CriticalExploitationNo known exploitationNot in CISA KEV, which does not prove it is unexploitedCISA KEV
Exploit odds (EPSS)0.45%Chance of exploitation activity in the next 30 days, higher than 38% of CVEs. Scored 23 Oct 2026FIRST EPSS
What fixes it
- 23.2R2-S7.7Junos OSCVE List
- 23.4R2-S8.13Junos OSCVE List
- 24.2R2-S5.5Junos OSCVE List
- 24.4R2-S5Junos OSCVE List
- 25.2R2-S2Junos OSCVE List
- 25.4R1-S3Junos OSCVE List
Show all 16 fixed versions
- 26.2R1-S2Junos OSCVE List
- 23.2R2-S7.7-EVOJunos OS EvolvedCVE List
- 23.4R2-S8.11-EVOJunos OS EvolvedCVE List
- 24.2R2-S5.6-EVOJunos OS EvolvedCVE List
- 24.4R2-S5-EVOJunos OS EvolvedCVE List
- 25.2R2-S2-EVOJunos OS EvolvedCVE List
- 25.4R1-S3-EVOJunos OS EvolvedCVE List
- 26.2R1-S2-EVOJunos OS EvolvedCVE List
- 25.2X100-D35-EVOJunos OS EvolvedCVE List
- 25.4X300-D40-EVOJunos OS EvolvedCVE List
A fixed version on one release line is not the upgrade target for every line. Check your exact version and any vendor backports.
Description
A Stack-based Buffer Overflow vulnerability in the BGP routing daemon of Juniper Networks Junos OS and Junos OS Evolved allows a configured BGP flowspec peer to cause routing-engine compromise or a routing-daemon denial of service via flowspec route re-advertisement when BGP update-threading is enabled.
Text from CVE List
Affected versions 17
- Junos OSaffected: all versions before 23.2R2-S7.7CVE List
- Junos OSaffected: 23.4 before 23.4R2-S8.13CVE List
- Junos OSaffected: 24.2 before 24.2R2-S5.5CVE List
- Junos OSaffected: 24.4 before 24.4R2-S5CVE List
- Junos OSaffected: 25.2 before 25.2R2-S2CVE List
- Junos OSaffected: 25.4 before 25.4R1-S3CVE List
- Junos OSaffected: 26.2 before 26.2R1-S2CVE List
- Junos OS Evolvedaffected: all versions before 23.2R2-S7.7-EVOCVE List
- Junos OS Evolvedaffected: 23.4 before 23.4R2-S8.11-EVOCVE List
- Junos OS Evolvedaffected: 24.2 before 24.2R2-S5.6-EVOCVE List
- Junos OS Evolvedaffected: 24.4 before 24.4R2-S5-EVOCVE List
- Junos OS Evolvedaffected: 25.2 before 25.2R2-S2-EVOCVE List
- Junos OS Evolvedaffected: 25.4 before 25.4R1-S3-EVOCVE List
- Junos OS Evolvedaffected: 26.2 before 26.2R1-S2-EVOCVE List
- Junos OS Evolvedaffected: 23.4X100CVE List
- Junos OS Evolvedaffected: 25.2X100 before 25.2X100-D35-EVOCVE List
- Junos OS Evolvedaffected: 25.4X300 before 25.4X300-D40-EVOCVE List