CISCO Security Advisory
Published Date: Not specified
CVE: CVE-2026-20218
Advisory Summary
🚨 ⚠️ Cisco Snort 3 VBA Decompression Buffer Overflow → DoS (CVE-2026-20218)
⚠️ What’s happening
Cisco reports a vulnerability in the Snort 3 Visual Basic for Applications (VBA) Decompression Engine present across multiple Cisco products. A remote attacker can trigger the Snort 3 Detection Engine to restart unexpectedly, leading to a Denial of Service (DoS) condition.
- Improper range checking during decompression of user-controlled VBA data
- Crafted inputs may cause stack data overflow, resulting in service instability/DoS
- Unauthenticated attacker sends crafted VBA data to a targeted device running the affected Snort 3 components
- Outcome: unexpected restarts / disruption of detection capabilities (availability impact)
- ✅ Software updates are available to remediate the issue
- 🧩 A workaround exists (details are included in Cisco’s advisory)
- Severity/Impact rating: Medium
- CVE: CVE-2026-20218
🧯 Market & operations priorities (actionable)
1. Inventory Cisco deployments using Snort 3 (and specifically the affected VBA decompression path).
2. Prioritize patching for internet-facing or high-signal inspection points where availability of IDS/IPS is critical.
3. Validate workaround effectiveness in your environment if patching is staged.
4. Monitor for Snort 3 restarts and related service instability after changes and during the interim period.
📌
-2026-20218
Reference: Vendor Advisory