CVE-2026-24184 Overview
CVE-2026-24184 is a buffer overflow vulnerability in the Link Layer Discovery Protocol (LLDP) daemon component of NVIDIA Cumulus Linux. An unauthenticated attacker positioned on an adjacent network can trigger the flaw by sending crafted LLDP frames to a vulnerable switch. A successful exploit may lead to code execution on the affected device.
The weakness is classified as [CWE-120] Buffer Copy without Checking Size of Input. Because Cumulus Linux runs on data-center network switches, exploitation could compromise fabric-level infrastructure and provide attackers with a foothold in the network control plane.
Critical Impact
Successful exploitation may result in arbitrary code execution on network switches running NVIDIA Cumulus Linux, compromising the integrity of the network fabric.
Affected Products
- NVIDIA Cumulus Linux (LLDP daemon component)
- Network switches running vulnerable Cumulus Linux versions
- Data center fabric devices exposing LLDP on adjacent Layer 2 segments
Discovery Timeline
- 2026-08-18 - CVE-2026-24184 published to NVD
- 2026-08-20 - Last updated in NVD database
Technical Details for CVE-2026-24184
Vulnerability Analysis
The vulnerability resides in the LLDP daemon that parses incoming Link Layer Discovery Protocol frames on Cumulus Linux switches. LLDP is a Layer 2 protocol used by network devices to advertise identity, capabilities, and neighbors on a local segment. The daemon copies attacker-controlled data from a crafted LLDP frame into a fixed-size buffer without adequately validating the input length.
When a malformed LLDP Type-Length-Value (TLV) field exceeds the expected boundary, adjacent memory is overwritten. This memory corruption can be leveraged to alter control-flow structures and achieve code execution in the context of the LLDP daemon. Exploitation requires the attacker to be on an adjacent network segment, since LLDP frames are not routed across Layer 3 boundaries.
Root Cause
The root cause is unchecked buffer copy operations during LLDP frame parsing [CWE-120]. The daemon trusts length fields or fixed offsets inside attacker-supplied TLVs and writes beyond the allocated buffer. The high attack complexity indicates that exploitation likely depends on specific memory layout conditions or bypass of mitigations such as ASLR and stack canaries.
Attack Vector
An attacker must have Layer 2 access to a network segment attached to a vulnerable switch. This can occur through a compromised endpoint, a rogue device plugged into a switch port, or a compromised adjacent switch. No authentication or user interaction is required. The attacker crafts LLDP frames containing malformed TLVs and transmits them to the target switch, where the LLDP daemon processes the frame and triggers the overflow.
No public proof-of-concept exploit is currently available, and the vulnerability is not listed in the CISA Known Exploited Vulnerabilities catalog. The EPSS probability is 0.272%.
Detection Methods for CVE-2026-24184
Indicators of Compromise
- Unexpected restarts or crashes of the lldpd process on Cumulus Linux switches
- LLDP frames containing oversized or malformed TLV fields observed in packet captures
- Anomalous outbound connections originating from a switch management interface
- New or unexpected LLDP neighbors appearing on switch ports connected to untrusted devices
Detection Strategies
- Monitor switch syslogs for LLDP daemon crashes, segmentation faults, or watchdog restarts
- Perform packet inspection at aggregation points to identify malformed LLDP frames
- Baseline LLDP neighbor tables and alert on unexpected changes or previously unseen chassis IDs
- Correlate switch process telemetry with network access events on the same port
Monitoring Recommendations
- Forward Cumulus Linux system and daemon logs to a centralized SIEM for long-term retention and correlation
- Track LLDP frame volumes per port and alert on sudden spikes from access ports
- Alert on any process restart of lldpd outside of scheduled maintenance windows
How to Mitigate CVE-2026-24184
Immediate Actions Required
- Review the NVIDIA product security advisory and identify Cumulus Linux versions running in the environment
- Apply the vendor-supplied patch to all affected switches as soon as it is available
- Restrict physical and logical access to switch ports on segments where untrusted devices could be connected
- Audit LLDP configuration on edge and access switches
Patch Information
NVIDIA has published a security resource for this issue at the NVIDIA product-security repository. Administrators should consult the NVD entry for CVE-2026-24184 and the CVE.org record for updated fixed versions and upgrade guidance.
Workarounds
- Disable the LLDP daemon on switch ports that face untrusted devices if operational requirements permit
- Enforce port security and 802.1X authentication on access ports to prevent rogue Layer 2 devices
- Segment management and data-plane traffic and restrict which VLANs process LLDP frames from endpoints
- Deploy network access control to block unauthorized devices from adjacent segments
# Example: disable LLDP on an untrusted access port in Cumulus Linux
# (adjust interface name to match your environment)
net add interface swp1 lldp disable
net commit
# Verify LLDP is disabled on the port
net show interface swp1 lldp
Disclaimer: This content was generated using AI. While we strive for accuracy, please verify critical information with official sources.
