---
title: "CVE-2026-102077: Juniper Networks Junos OS - Denial of Service"
description: "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."
url: https://panop.io/threat-heartbeat/CVE-2026-102077/
---

# 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 ↗](https://nvd.nist.gov/vuln/detail/CVE-2026-102077)

## 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](https://cwe.mitre.org/data/definitions/754.html)

## 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

- [https://nvd.nist.gov/vuln/detail/CVE-2026-102077](https://nvd.nist.gov/vuln/detail/CVE-2026-102077)
- [https://supportportal.juniper.net/JSA112182](https://supportportal.juniper.net/JSA112182)

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## What this record can't tell you

- Whether you run the affected software, and where
- Whether an attacker can actually reach and exploit it
- The misconfigurations that never get a CVE number
- What it would cost the business, ranked into what to fix first

Panop answers these inside your environment, for this CVE and every other finding.

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