CVE-2011-1640: The ethernet-lldp component in Cisco IOS 12.2 before 12.2(33)SXJ1 does not properly support a large number...

Security readout for executives and security teams

This CVE describes a Cisco IOS LLDP handling flaw that can crash an affected device when it receives crafted LLDP data with many Management Address TLVs. The known impact is denial of service, not data theft or remote code execution. Source data does not provide CVSS scoring or broad affected-product detail. Exposure is most likely on Cisco IOS 12.2 builds before 12.2(33)SXJ1 where the ethernet-lldp component processes LLDPDUs. The CVE source names Cisco IOS and a Catalyst 6500 12.2SX release-note reference, but the affected-product metadata is incomplete. Treat this as an availability risk for legacy Cisco infrastructure. It warrants prompt inventory and upgrade planning where affected versions remain in production, especially on devices supporting critical network segments. There is no source-backed evidence here of active exploitation. Mitigation focus: Check Cisco release notes and advisories for CSCtj22354 guidance.; Upgrade affected Cisco IOS 12.2 deployments to 12.2(33)SXJ1 or later where applicable.; Inventory devices running Cisco IOS 12.2 before 12.2(33)SXJ1..

Prepared

Jun 27, 2026, 17:48 UTC (UTC+00:00)

Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.