Junos OS: EX4100 Series, EX4400: With sFlow configured in a VC scenario multicast traffic leads to an FPC crash
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Fixed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA. Impact type from CWE-401.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Juniper | Junos OS | before 23.2R2-S7; 23.4 to before 23.4R2-S7; 24.2 to before 24.2R2-S4; 24.4 to before 24.4R2 | 23.2R2-S7, 23.4R2-S7, 24.2R2-S4, 24.4R2 | Patch available | CNA |
- Junos OS VendorJuniper Affected before 23.2R2-S7; 23.4 to before 23.4R2-S7; 24.2 to before 24.2R2-S4; 24.4 to before 24.4R2 Fixed in 23.2R2-S7, 23.4R2-S7, 24.2R2-S4, 24.4R2 Patch available CNA
CPE configurations NVD · 40
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* | before 23.2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:* | 23.2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:* | 23.2 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:* | 23.2 r1-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:* | 23.2 r1-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r2:*:*:*:*:*:* | 23.2 r2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r2-s1:*:*:*:*:*:* | 23.2 r2-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:* | 23.2 r2-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r2-s3:*:*:*:*:*:* | 23.2 r2-s3 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r2-s4:*:*:*:*:*:* | 23.2 r2-s4 | Vulnerable | Juniper |
- cpe:2.3:o:juniper:junos:*:*:*:*:*:*:*:* Versions before 23.2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:-:*:*:*:*:*:* Versions 23.2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r1:*:*:*:*:*:* Versions 23.2 r1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r1-s1:*:*:*:*:*:* Versions 23.2 r1-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r1-s2:*:*:*:*:*:* Versions 23.2 r1-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r2:*:*:*:*:*:* Versions 23.2 r2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r2-s1:*:*:*:*:*:* Versions 23.2 r2-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r2-s2:*:*:*:*:*:* Versions 23.2 r2-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r2-s3:*:*:*:*:*:* Versions 23.2 r2-s3 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r2-s4:*:*:*:*:*:* Versions 23.2 r2-s4 Vulnerable ·Juniper
Show 30 more CPE
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:juniper:junos:23.2:r2-s5:*:*:*:*:*:* | 23.2 r2-s5 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.2:r2-s6:*:*:*:*:*:* | 23.2 r2-s6 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:* | 23.4 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:* | 23.4 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:* | 23.4 r1-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r1-s2:*:*:*:*:*:* | 23.4 r1-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:* | 23.4 r2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:* | 23.4 r2-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:* | 23.4 r2-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:* | 23.4 r2-s3 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s4:*:*:*:*:*:* | 23.4 r2-s4 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s5:*:*:*:*:*:* | 23.4 r2-s5 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:23.4:r2-s6:*:*:*:*:*:* | 23.4 r2-s6 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:* | 24.2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:* | 24.2 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:* | 24.2 r1-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:* | 24.2 r1-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r2:*:*:*:*:*:* | 24.2 r2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r2-s1:*:*:*:*:*:* | 24.2 r2-s1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r2-s2:*:*:*:*:*:* | 24.2 r2-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.2:r2-s3:*:*:*:*:*:* | 24.2 r2-s3 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.4:-:*:*:*:*:*:* | 24.4 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.4:r1:*:*:*:*:*:* | 24.4 r1 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.4:r1-s2:*:*:*:*:*:* | 24.4 r1-s2 | Vulnerable | Juniper |
| cpe:2.3:o:juniper:junos:24.4:r1-s3:*:*:*:*:*:* | 24.4 r1-s3 | Vulnerable | Juniper |
| cpe:2.3:h:juniper:ex4100:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ex4100-f:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ex4100-h:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ex4100-h-12t:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
| cpe:2.3:h:juniper:ex4400:-:*:*:*:*:*:*:* | not specified by NVD | Running on | Juniper |
- cpe:2.3:o:juniper:junos:23.2:r2-s5:*:*:*:*:*:* Versions 23.2 r2-s5 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.2:r2-s6:*:*:*:*:*:* Versions 23.2 r2-s6 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:-:*:*:*:*:*:* Versions 23.4 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r1:*:*:*:*:*:* Versions 23.4 r1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r1-s1:*:*:*:*:*:* Versions 23.4 r1-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r1-s2:*:*:*:*:*:* Versions 23.4 r1-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2:*:*:*:*:*:* Versions 23.4 r2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s1:*:*:*:*:*:* Versions 23.4 r2-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s2:*:*:*:*:*:* Versions 23.4 r2-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s3:*:*:*:*:*:* Versions 23.4 r2-s3 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s4:*:*:*:*:*:* Versions 23.4 r2-s4 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s5:*:*:*:*:*:* Versions 23.4 r2-s5 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:23.4:r2-s6:*:*:*:*:*:* Versions 23.4 r2-s6 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:-:*:*:*:*:*:* Versions 24.2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r1:*:*:*:*:*:* Versions 24.2 r1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r1-s1:*:*:*:*:*:* Versions 24.2 r1-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r1-s2:*:*:*:*:*:* Versions 24.2 r1-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r2:*:*:*:*:*:* Versions 24.2 r2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r2-s1:*:*:*:*:*:* Versions 24.2 r2-s1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r2-s2:*:*:*:*:*:* Versions 24.2 r2-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.2:r2-s3:*:*:*:*:*:* Versions 24.2 r2-s3 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.4:-:*:*:*:*:*:* Versions 24.4 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.4:r1:*:*:*:*:*:* Versions 24.4 r1 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.4:r1-s2:*:*:*:*:*:* Versions 24.4 r1-s2 Vulnerable ·Juniper
- cpe:2.3:o:juniper:junos:24.4:r1-s3:*:*:*:*:*:* Versions 24.4 r1-s3 Vulnerable ·Juniper
- cpe:2.3:h:juniper:ex4100:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ex4100-f:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ex4100-h:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ex4100-h-12t:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
- cpe:2.3:h:juniper:ex4400:-:*:*:*:*:*:*:* Versions not specified by NVD Running on ·Juniper
Remediation
- Fix · CNA Junos OS (Juniper Networks) Fixed in 23.2R2-S7, 23.4R2-S7, 24.2R2-S4, 24.4R2
Timeline
- 2026-10-02 Threatist record created from CVE-2026-57027
- 2026-10-03 Alias added: GHSA-2xj6-hwhm-5m6g
References
More Juniper Junos vulnerabilities
- TI-2023-18638 Junos OS: EX and SRX Series: A PHP vulnerability in J-Web allows an unauthenticated to… KEVCVSS 3.1CRITICAL 9.8
- TI-2020-01585 Out of Cycle Security Advisory: Junos OS: Security vulnerability in J-Web and web based (HTTP/HTTPS) services KEVCVSS 3.1CRITICAL 9.8
- TI-2015-04610 Assertion failure in ISC BIND named via TKEY queries KEVCVSS 3.1HIGH 7.5
- TI-2025-15550 Junos OS: An local attacker with shell access can execute arbitrary code KEVCVSS 4.0MEDIUM 6.7
- TI-2023-18644 Junos OS: SRX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload and download arbitrary files KEVCVSS 3.1MEDIUM 5.3
- TI-2023-18640 Junos OS: EX Series: A vulnerability in J-Web allows an unauthenticated attacker to upload arbitrary files KEVCVSS 3.1MEDIUM 5.3
Sources
- CVE-2026-57027 · CVE Program
- CVE-2026-57027 · NVD
- FIRST EPSS
- GHSA-2xj6-hwhm-5m6g · GitHub Advisory Database · CC BY 4.0
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