CVE-2026-57027 Details
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.
A memory leak vulnerability has been identified in the packet forwarding engine of Juniper Networks Junos OS, specifically on EX4100 and EX4400 Series devices. This vulnerability allows an unauthenticated adjacent attacker to cause a denial-of-service condition. The issue arises when sFlow is enabled for multicast in a Virtual Chassis scenario, leading to a memory leak as multicast traffic is improperly managed between VC members. This memory leak can be monitored through the 'show chassis fpc' command, as it causes a continuous increase in buffer values. Eventually, the memory leak leads to a crash and restart of the affected forwarding plane component (FPC).
Users can upgrade to Junos OS versions 23.2R2-S7, 23.4R2-S7, 24.2R2-S4, 24.4R2, 25.2R1, or any subsequent release to address this vulnerability. Instructions for upgrading can be found on the Juniper Networks Customer Support website.
Metrics
CVSS 4.0 Severity and Vector Strings:
CVSS 3.x Severity and Vector Strings:
No data available for CVSS Version 2.0 on this CVE.
CISA-ADP
Assessed Jul 10, 2026References to Advisories, Solutions, and Tools
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| URL | Source(s) | Tag(s) |
|---|---|---|
| https://supportportal.juniper.net/JSA110087 | [email protected] | Vendor Advisory |
Weakness Enumeration
| CWE-ID | CWE Name | Source |
|---|---|---|
| CWE-401 | Missing Release of Memory after Effective Lifetime | [email protected] |
Affected Products
| Product | Versions |
|---|---|
| juniper junos | < 23.2 23.2 - 23.2 r1 23.2 r1-s1 23.2 r1-s2 23.2 r2 23.2 r2-s1 23.2 r2-s2 23.2 r2-s3 23.2 r2-s4 23.2 r2-s5 23.2 r2-s6 23.4 - 23.4 r1 23.4 r1-s1 23.4 r1-s2 23.4 r2 23.4 r2-s1 23.4 r2-s2 23.4 r2-s3 23.4 r2-s4 23.4 r2-s5 23.4 r2-s6 24.2 - 24.2 r1 24.2 r1-s1 24.2 r1-s2 24.2 r2 24.2 r2-s1 24.2 r2-s2 24.2 r2-s3 24.4 - 24.4 r1 24.4 r1-s2 24.4 r1-s3 |
CPE
Remediation
| |
| juniper ex4100 | All versions |
CPE
Remediation
| |
| juniper ex4100-f | All versions |
CPE
Remediation
| |
| juniper ex4100-h | All versions |
CPE
Remediation
| |
| juniper ex4100-h-12t | All versions |
CPE
Remediation
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| juniper ex4400 | All versions |
CPE
Remediation
| |
Change History
3 change records found show changes
| Date | Action | Recorded By |
|---|---|---|
| Jul 13, 2026 | Initial Analysis | [email protected] |
| Jul 10, 2026 | CVE Modified | CISA-ADP |
| Jul 9, 2026 | New CVE Received | [email protected] |