CISCO Security Advisory
Published Date: Not specified
CVE: CVE-2026-76445
Advisory Summary
🧩 ⛔ Multiple Cisco Products: Snort 3 Remote DoS via GTP Codec Logic Flaw
⚠️ Alarm: Cisco disclosed a Medium security issue affecting multiple Cisco products that run the Snort 3 Detection Engine. A remote attacker can trigger an unexpected restart and, in the worst case, push the detection engine into an infinite loop, resulting in a Denial of Service (DoS).
🔍 What’s happening (root cause):
The vulnerability is caused by flawed logic when GPRS Tunneling Protocol (GTP) extension headers are processed inside the Snort 3 codec.
🎯 Attack scenario (how it’s exploited):
An attacker can send a crafted, fragmented UDP datagram containing GTP headers to the Snort 3 Detection Engine on an affected device. Successful exploitation can lead to the engine entering an infinite loop → service disruption.
🛠️ Fix status:
✅ Cisco has released software updates to address the vulnerability.
🧰 Cisco also provides workarounds to mitigate risk while updates are applied.
🔐 Vulnerability identifier: CVE-2026-76445
📌 Actionable recommendations for market/ops teams:
1) Prioritize patching for all impacted deployments running Snort 3 Detection Engine (follow Cisco’s advisory guidance and target versions).
2) Inventory exposure: identify devices/interfaces where Snort 3 receives UDP traffic and where GTP parsing is enabled.
3) Apply workarounds immediately for any systems not yet patchable, especially those at the edge receiving untrusted traffic.
4) Validate detection availability post-change (monitor for unexpected restarts and inspection throughput anomalies).
5) Use this event to review DoS resilience of inline/inspection components in the security stack (CPU pinning, restart loops, watchdog behavior).
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Reference: Vendor Advisory