Junos OS l2cpd crash when FNP runs with VLAN-VPLS encapsulation
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-770.
Summary
Juniper Networks Junos OS releases before 23.2R2-S7.7, from 23.4 before 23.4R2-S8.13, and other listed release lines are affected on all platforms except PTX Series and SRX Series. The l2cpd process allocates resources without limits or throttling (CWE-770), so an adjacent unauthenticated attacker can cause a denial of service and restart l2cpd when FNP is enabled on a VPLS routing instance with VLAN-VPLS encapsulation.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
Description from the CNA
An Allocation of Resources Without Limits or Throttling vulnerability in the l2cpd process of Juniper Networks Junos OS allows an adjacent unauthenticated attacker to cause a denial of service and l2cpd restart via FNP-enabled Layer 2 interfaces. The issue is triggered when the FNP feature is enabled on a VPLS routing instance with VLAN-VPLS encapsulation enabled. This issue affects all platforms except the PTX Series and SRX Series.
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-S7.7; 23.4 to before 23.4R2-S8.13; 24.2 to before 24.2R2-S5.5; 24.4 to before 24.4R2-S5; 25.2 to before 25.2R2-S2; 25.4 to before 25.4R1-S3; 26.2 to before 26.2R1-S2 | 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 26.2R1-S2 | Patch available | CNA |
- Junos OS VendorJuniper Affected before 23.2R2-S7.7; 23.4 to before 23.4R2-S8.13; 24.2 to before 24.2R2-S5.5; 24.4 to before 24.4R2-S5; 25.2 to before 25.2R2-S2; 25.4 to before 25.4R1-S3; 26.2 to before 26.2R1-S2 Fixed in 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 26.2R1-S2 Patch available CNA
Remediation
Upgrade Junos OS to 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, or 26.2R1-S2 or later fixed releases of the same release line.
Written with Claude Haiku 5.5 from the sources below · 2026-10-28
- Fix · CNA Junos OS (Juniper Networks) Fixed in 23.2R2-S7.7, 23.4R2-S8.13, 24.2R2-S5.5, 24.4R2-S5, 25.2R2-S2, 25.4R1-S3, 26.2R1-S2
Fixed in the same release
Records fixed by the same vendor advisory or release, as the CNA lists them.
- Advisory ·
Juniper Networks Junos OS — supportportal.juniper.net/JSA112188
11 records Highest priority Priority MEDIUM 8 MEDIUM, 3 LOW
Other records, highest priority first
- TI-2026-74194 Improper authentication in Junos OS J-Web allows root command executionPriority MEDIUM 49
- TI-2026-74283 Reachable assertion in Junos OS TWAMP client disrupts rmopd servicePriority MEDIUM 46
- TI-2026-74208 Integer underflow in Juniper Junos OS lets attackers crash the kernelPriority MEDIUM 46
Timeline
- 2026-10-15 Threatist record created from CVE-2026-102048
References
More Juniper 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-2015-06436 Juniper ScreenOS 6.2.0r15 through 6.2.0r18, 6.3.0r12 before 6.3.0r12b, 6.3.0r13 before… KEVCVSS 3.1CRITICAL 9.8
- TI-2022-20885 Apache Commons Text prior to 1.10.0 allows RCE when applied to untrusted input due to insecure interpolation defaults CVSS 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
Sources
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences