Junos OS: EX4100 Series, EX4400: With sFlow configured in a VC scenario multicast traffic leads to an FPC crash
Summary
| CVE | CVE-2026-57027 |
|---|---|
| State | PUBLISHED |
| Assigner | juniper |
| Source Priority | CVE Program / NVD first with legacy fallback |
| Published | 2026-07-09 22:17:08 UTC |
| Updated | 2026-07-10 17:49:57 UTC |
| Description | A Missing Release of Memory after Effective Lifetime vulnerability in the packet forwarding engine (pfe) of Juniper Networks Junos OS on specific EX Series devices allows an unauthenticated adjacent attacker to cause a Denial-of-Service (DoS).When sFlow is configured in a Virtual Chassis (VC) scenario with EX4100 Series or EX4400 Series devices, multicast traffic which is received on one VC member and sent out on another member leads to a memory leak and ultimately an FPC crash and restart. The leak can be monitored by watching the continuous increase of the buffer values in the output of: user@host> show chassis fpc This issue affects Junos OS on EX4100 Series and EX4400: * all versions before 23.2R2-S7, * 23.4 versions before 23.4R2-S7, * 24.2 versions before 24.2R2-S4, * 24.4 versions before 24.4R2. |
Risk And Classification
Primary CVSS: v4.0 7.1 HIGH from [email protected]
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:X/RE:M/U:X
EPSS: 0.002690000 probability, percentile 0.185630000 (date 2026-07-11)
Problem Types: CWE-401 | CWE-401 CWE-401 Missing Release of Memory after Effective Lifetime
| Version | Source | Type | Score | Severity | Vector |
|---|---|---|---|---|---|
| 4.0 | [email protected] | Secondary | 7.1 | HIGH | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/C... |
| 4.0 | CNA | CVSS | 7.1 | HIGH | CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/AU:Y/... |
| 3.1 | [email protected] | Secondary | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
| 3.1 | CNA | CVSS | 6.5 | MEDIUM | CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H |
CVSS v4.0 Breakdown
CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:L/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:Y/R:A/V:X/RE:M/U:X
CVSS v3.1 Breakdown
CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
Vendor Declared Affected Products
| Source | Vendor | Product | Version | Platforms |
|---|---|---|---|---|
| CNA | Juniper Networks | Junos OS | affected 23.2R2-S7 custom | EX4100 Series, EX4400 Series |
| CNA | Juniper Networks | Junos OS | affected 23.4 23.4R2-S7 custom | EX4100 Series, EX4400 Series |
| CNA | Juniper Networks | Junos OS | affected 24.2 24.2R2-S4 custom | EX4100 Series, EX4400 Series |
| CNA | Juniper Networks | Junos OS | affected 24.4 24.4R2 custom | EX4100 Series, EX4400 Series |
References
| Reference | Source | Link | Tags |
|---|---|---|---|
| supportportal.juniper.net/JSA110087 | [email protected] | supportportal.juniper.net | |
| CVE Program record | CVE.ORG | www.cve.org | canonical |
| NVD vulnerability detail | NVD | nvd.nist.gov | canonical, analysis |
Additional Advisory Data
Solutions
CNA: The following software releases have been updated to resolve this specific issue: Junos OS: 23.2R2-S7, 23.4R2-S7, 24.2R2-S4, 24.4R2, 25.2R1, and all subsequent releases.
Workarounds
CNA: There are no known workarounds for this issue.
Exploits
CNA: Juniper SIRT is not aware of any malicious exploitation of this vulnerability.