CVE-2026-102077 Juniper Networks Junos OS - Denial of Service

Juniper Networks Junos OS on MX Series with SPC3 contains a denial-of-service vulnerability caused by improper handling of malformed IPv6 packets in the Packet Forwarding Engine, letting unauthenticated network attackers exhaust NAT resources, exploit requires source NAT configuration.

CVSS base score 7.5 /10
High
CISA KEV
Not listed
Public exploit
None known
Authentication
Not required
View the NVD record ↗

Details

Type
Denial of Service
Impact
Denial Of Service
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Published
14 October 2026
Updated
15 October 2026
Weakness
CWE-754

Vendor fix

Update to Junos OS versions 23.2R2-S4 or later, 23.4R2-S5 or later, or 24.2R2 or later.

Patching closes this CVE. It does not tell you which of your systems run the affected version, or what else is exposed alongside them.

References

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