# CVE-2026-102049: Juniper Networks Junos OS stack-based buffer overflow in l2cpd

Source: https://junglewise.ai/threats/cve-2026-102049-a-stack-based-buffer-overflow-vulnerability-in-the-l2cpd-process  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2026-10-14. Updated: 2026-10-16  
License: CC BY 4.0 with a link back

CVE-2026-102049 · Severity: high · CVSS 8.8 · Published 2026-10-14

Juniper Junos OS is network routing software used to manage enterprise networks. A stack-based buffer overflow in the l2cpd process can allow an adjacent attacker on the network to crash the device or gain root-level control by sending specially crafted LLDP link-layer discovery packets. This affects devices with Unified Access Policy enabled, potentially causing extended network outages or complete system compromise.

Technologies: [Juniper Networks Junos OS](https://junglewise.ai/threats/technologies/juniper-networks-junos-os), [Juniper Networks Junos OS Evolved](https://junglewise.ai/threats/technologies/junos-os-evolved). Vendors: [Juniper Networks](https://junglewise.ai/threats/vendors/juniper-networks).

## Quick answers

**Is CVE-2026-102049 exploited in the wild?** No. Junglewise Threat Intelligence has no report of CVE-2026-102049 being exploited in the wild.

**How severe is CVE-2026-102049?** High severity, with a CVSS score of 8.8, published 14 October 2026.

**Which products and versions are affected?** Juniper Networks Junos OS; Juniper Networks Junos OS Evolved.

**Is there a fix for CVE-2026-102049?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2026-102049 attacked?** It is attacked from the adjacent network or over the network, in an operating system.

**Am I affected by CVE-2026-102049?** Check whether you run Juniper Networks Junos OS or Juniper Networks Junos OS Evolved. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Technical details

A stack-based buffer overflow exists in the l2cpd (Layer 2 Control Protocol daemon) process when processing LLDP (Link Layer Discovery Protocol) traffic on interfaces with Unified Access Policy enabled. An adjacent unauthenticated attacker can trigger the overflow via malformed LLDP packets, leading to denial of service or arbitrary code execution with root privileges. The attack requires network adjacency but no prior authentication.

## Affected products

- Juniper Networks Junos OS
- Juniper Networks Junos OS Evolved

## Timeline

- 2026-10-14: disclosed

## References

- [https://supportportal.juniper.net/JSA112187](https://supportportal.juniper.net/JSA112187)

## Related threats

- [Juniper Networks Junos OS stack buffer overflow in BGP/EVPN](https://junglewise.ai/threats/cve-2026-101982-a-stack-based-buffer-overflow-vulnerability-in-the-routing)
- [Juniper Networks Junos OS stack buffer overflow in rpd](https://junglewise.ai/threats/cve-2026-101981-a-stack-based-buffer-overflow-vulnerability-in-the-routing)
- [Juniper Junos OS routing protocol daemon crash in ISO-VPN](https://junglewise.ai/threats/cve-2026-101952-an-improper-validation-of-consistency-within-input-vulnerability)
- [Juniper Networks Junos OS stack buffer overflow in BGP routing daemon](https://junglewise.ai/threats/cve-2026-102178-a-stack-based-buffer-overflow-vulnerability-in-the-bgp-routing)
- [Juniper Junos buffer overflow in SDK service process](https://junglewise.ai/threats/cve-2026-102176-a-buffer-copy-without-checking-size-of-input-classic-buffer)