Junos OS: MX Series with SPC3: In a source NAT scenario malformed packets will lead to resource leaks and eventually traffic stops
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.
CVE-2026-102077
Primary source · Revision 1
Imported from structured advisory data. Source references identify upstream records or fields; verify affected versions and your deployed configuration.
Security context
Source reference: cve:CVE-2026-102077
Junos OS
Source reference: /containers/cna/affected/0/product
- Affected versions
- Not stated in this record
- Fixed versions
- Not stated in this record
- Prerequisites
- Not stated in this record
Structured affected-version data
Original package identities and version rules from this source.
[
{
"vendor": "Juniper Networks",
"product": "Junos OS",
"versions": [
{
"status": "affected",
"version": "0",
"lessThan": "23.2R2-S4",
"versionType": "custom"
},
{
"status": "affected",
"version": "23.4",
"lessThan": "23.4R2-S5",
"versionType": "custom"
},
{
"status": "affected",
"version": "24.2",
"lessThan": "24.2R2",
"versionType": "custom"
}
],
"platforms": [
"MX Series with SPC3"
],
"defaultStatus": "unaffected"
}
]- Related CVEs
- CVE-2026-102077
Source reference:
/cveMetadata/cveId
Publisher severity
high
Source reference: /containers/cna/metrics
- Event
- #23185 · Revision 1
- Added to Heist Feed
- Publisher date