On MX Series with SPC3 line-card and source NAT configuration, when a specific malformed IPv6 packet is received, it is not dropped but instead a session is created and NAT resources are allocated. Continued receipt of such packets will eventually lead to session or resource exhaustion, which will impact all traffic through the device. To recover the device needs to be rebooted.
To monitor session usage, use the following:
show services sessions summary
To monitor source NAT resource usage, use the following:
show services nat pool
This issue affects Junos OS on MX Series with SPC3:
* All versions before 23.2R2-S4;
* 23.4 versions before 23.4R2-S5;
* 24.2 versions before 24.2R2.
No analysis available yet.
Vendor Solution
The following software releases have been updated to resolve this specific issue: Junos OS: 23.2R2-S4, 23.4R2-S5, 24.2R2, 24.4R1, and all subsequent releases.
Vendor Workaround
There are no known workarounds for this issue.
Tracking
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No advisories yet.
| Link | Providers |
|---|---|
| https://supportportal.juniper.net/JSA112182 |
|
Wed, 14 Oct 2026 17:30:00 +0000
| Type | Values Removed | Values Added |
|---|---|---|
| Description | An Improper Check for Unusual or Exceptional Conditions vulnerability in the Packet Forwarding Engine (PFE) of Juniper Networks Junos OS on MX Series with SPC3 allows an unauthenticated, network-based attacker to cause a Denial-of-Service (DoS). On MX Series with SPC3 line-card and source NAT configuration, when a specific malformed IPv6 packet is received, it is not dropped but instead a session is created and NAT resources are allocated. Continued receipt of such packets will eventually lead to session or resource exhaustion, which will impact all traffic through the device. To recover the device needs to be rebooted. To monitor session usage, use the following: show services sessions summary To monitor source NAT resource usage, use the following: show services nat pool This issue affects Junos OS on MX Series with SPC3: * All versions before 23.2R2-S4; * 23.4 versions before 23.4R2-S5; * 24.2 versions before 24.2R2. | |
| Title | Junos OS: MX Series with SPC3: In a source NAT scenario malformed packets will lead to resource leaks and eventually traffic stops | |
| Weaknesses | CWE-754 | |
| References |
| |
| Metrics |
cvssV3_1
|
Subscriptions
No data.
Status: PUBLISHED
Assigner: juniper
Published:
Updated: 2026-10-14T17:14:01.511Z
Reserved: 2026-09-28T17:37:38.548Z
Link: CVE-2026-102077
No data.
Status : Received
Published: 2026-10-14T18:17:13.460
Modified: 2026-10-14T18:17:13.460
Link: CVE-2026-102077
No data.
OpenCVE Enrichment
No data.
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CWE-754
Improper Check for Unusual or Exceptional Conditions