What’s Vulnerable › Vulnerabilities

CVE-2026-33797: Junos OS and Junos OS Evolved: An attacker sending a specific genuine BGP packet causes a BGP reset

• Severity: high (CVSS 7.4 v3.1)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.2% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2026-04-09 · updated 2026-10-26
• Weakness: CWE-20

Description

An Improper Input Validation vulnerability in Juniper Networks Junos OS and Junos OS Evolved allows an unauthenticated, adjacent attacker, sending a specific genuine BGP packet in an already established BGP session to reset only that session causing a Denial of Service (DoS). An attacker repeatedly sending the packet will sustain the Denial of Service (DoS).This issue affects Junos OS: * 25.2 versions before 25.2R2 This issue does not affect Junos OS versions before 25.2R1. This issue affects Junos OS Evolved: * 25.2-EVO versions before 25.2R2-EVO This issue does not affect Junos OS Evolved versions before 25.2R1-EVO. eBGP and iBGP are affected. IPv4 and IPv6 are affected.

Affected products

• Juniper Junos OS: 25.2, 25.2-r1, 25.2-r1-s1, 25.2-r1-s2
• Juniper Networks Junos OS Evolved: 25.2, 25.2-r1, 25.2-r1-s1, 25.2-r1-s2

References

• https://kb.juniper.net/JSA107850
• https://supportportal.juniper.net/JSA107850

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