Exploited CVEs / Cisco / CVE-2018-0155
CVE-2018-0155
Cisco Catalyst Bidirectional Forwarding Detection Denial-of-Service Vulnerability. Exploitation in the wild is confirmed by CISA, not predicted. Federal agencies were required to remediate by 2022-03-17 (that deadline has passed); treat that date as the outer bound for your own environment. The fix is in the vendor advisory: Cisco Security Advisories (PSIRT), linked below.
Actively exploited Cisco Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches vulnerability, High severity, CVSS 8.6. Added to the CISA KEV catalog 2022-03-03.
Risk summary
Updated July 27, 2026. Data refreshed on every build from MSRC, CISA KEV, and FIRST EPSS.
Senserva AI Opinion for CVE-2018-0155
This flaw lets an unauthenticated remote attacker send crafted Bidirectional Forwarding Detection traffic to crash the iosd process on Catalyst 4500 and 4500-X switches, dropping the box into a denial-of-service state. Only these two switch families running BFD offload are affected, but because iosd is the core control process, a crash takes the whole switch offline. CISA confirmed active exploitation and added it to KEV on 2022-03-03, so distribution and core switching using these platforms is at real risk.
Do this: Identify any Catalyst 4500 or 4500-X switches with BFD enabled and apply the fixed Cisco IOS software release, or disable BFD offload if patching cannot happen immediately.
AI-generated from public data, 2026-07-21. Verify against the vendor advisory before acting.
Senserva AI Opinion and rich prompt for CVE-2018-0155
Copy this prompt into Claude, ChatGPT, or Copilot. The facts are included, sourced from this page.
Full tracking and change history for CVE-2018-0155
Published and last-revised dates are authoritative, from Microsoft MSRC (or the CISA KEV date-added). Senserva additionally records day-to-day changes from 2026-07-07, refreshed several times a day; the change count reflects that forward-only tracking.
CISA required action
Federal (BOD 22-01) remediation due date: 2022-03-17 (past due).
Apply updates per vendor instructions.
Official fix for CVE-2018-0155
The authoritative fix and affected-version list are published by the vendor. Find the Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches advisory on Cisco Security Advisories (PSIRT).
Common questions about CVE-2018-0155
Is CVE-2018-0155 actively exploited?
Yes. CVE-2018-0155 was added to the CISA Known Exploited Vulnerabilities (KEV) catalog on 2022-03-03, which means exploitation in the wild has been confirmed, not predicted. Its EPSS 30-day exploitation probability is 7.9%.
What is the CISA deadline and required action for CVE-2018-0155?
CISA set the federal (BOD 22-01) remediation due date at 2022-03-17, which has passed; treat any unremediated system as overdue. The verbatim required action: Apply updates per vendor instructions.
What fixes CVE-2018-0155?
The authoritative fix is in the vendor advisory: see Cisco Security Advisories (PSIRT) for the patched Catalyst 4500 Series Switches and Cisco Catalyst 4500-X Series Switches versions and any workarounds. KEV listing makes this a fix-first item: patch it ahead of higher-CVSS issues nobody is exploiting.
Can I ask my own AI about CVE-2018-0155?
Yes. This page includes a free, ready-to-paste AI prompt containing CVE-2018-0155's key facts: severity, CVSS, EPSS, the KEV date, the CISA due date, and the required action. Copy it into Claude, ChatGPT, or Copilot; the data is refreshed twice a day (5 AM and 3 PM US Central).
More exploited Cisco CVEs
The newest Cisco entries on the CISA KEV catalog:
All Cisco exploited CVEs on one page: Cisco vulnerabilities actively exploited.
Authoritative references
Every actively exploited CVE, searchable with due dates and CSV export: the exploited-CVE tracker. The newest additions: exploited this week.
