CVE-2026-20067
Description
Multiple Cisco products are affected by a vulnerability in the Snort 3 detection engine that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to restart, resulting in an interruption of packet inspection. This vulnerability is due to incomplete error checking when parsing the Multicast DNS fields of the HTTP header. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection to be parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine unexpectedly restarts.
How to fix
- cisco snort3.9.5.0 or later
Affected products
| Product | Affected versions | Fixed in |
|---|---|---|
| cisco snort | 3.0.0-233 ≤ v < 3.9.5.0 | 3.9.5.0 |
| cisco cyber_vision | 3.0.0, 3.0.1, 3.0.2, 3.0.3, 3.0.4, 3.0.5, 3.0.6, 3.1.0, 3.1.1, 3.1.2, 3.2.0, 3.2.1, 3.2.2, 3.2.3, 3.2.4, 4.0.0, 4.0.1, 4.0.2, 4.0.3, 4.1.0, 4.1.1, 4.1.2, 4.1.3, 4.1.4, 4.1.5, 4.1.6, 4.1.7, 4.2.0, 4.2.1, 4.2.2, 4.2.3, 4.2.4, 4.2.6, 4.3.0, 4.3.1, 4.3.2, 4.3.3, 4.4.0, 4.4.1, 4.4.2, 4.4.3, 5.0.0, 5.0.1, 5.0.2, 5.1.0, 5.1.1, 5.1.2, 5.1.3, 5.2.0, 5.2.1, 5.3.0, 5.3.1, 5.3.2 | — |
| cisco secure_firewall_threat_defense | 7.0.0, 7.0.0.1, 7.0.1, 7.0.1.1, 7.0.2, 7.0.2.1, 7.0.3, 7.0.4, 7.0.5, 7.0.6, 7.0.6.1, 7.0.6.2, 7.0.6.3, 7.0.7, 7.0.8, 7.0.8.1, 7.1.0, 7.1.0.1, 7.1.0.2, 7.1.0.3, 7.2.0, 7.2.0.1, 7.2.1, 7.2.2, 7.2.3, 7.2.4, 7.2.4.1, 7.2.5, 7.2.5.1, 7.2.5.2, 7.2.6, 7.2.7, 7.2.8, 7.2.8.1, 7.2.9, 7.2.10, 7.2.10.2, 7.3.0, 7.3.1, 7.3.1.1, 7.3.1.2, 7.4.0, 7.4.1, 7.4.1.1, 7.4.2, 7.4.2.1, 7.4.2.2, 7.4.2.3, 7.4.2.4, 7.4.3, 7.6.0, 7.6.1, 7.6.2, 7.6.2.1, 7.7.0, 7.7.10, 7.7.10.1 | — |
| cisco unified_threat_defense_snort_intrusion_prevention_system_engine | 17.2.1r, 17.3.1a, 17.3.2, 17.3.3, 17.3.4, 17.3.4a, 17.3.5, 17.3.6, 17.3.7, 17.3.8, 17.3.8a, 17.4.1a, 17.4.1b, 17.4.2, 17.5.1, 17.5.1a, 17.6.1a, 17.6.2, 17.6.3, 17.6.3a, 17.6.4, 17.6.5, 17.6.6, 17.6.6a, 17.6.7, 17.6.8, 17.6.8a, 17.7.1a, 17.7.2, 17.8.1a, 17.9.1a, 17.9.2a, 17.9.3a, 17.9.4, 17.9.4a, 17.9.5a, 17.9.5e, 17.9.5f, 17.9.6, 17.9.7a, 17.9.7b, 17.9.8, 17.10.1a, 17.11.1a, 17.12.1a, 17.12.2, 17.12.3, 17.12.3a, 17.12.4, 17.12.4a, 17.12.4b, 17.12.5, 17.12.5a, 17.12.5b, 17.12.5c, 17.12.5d, 17.12.6, 17.13.1a, 17.14.1a, 17.15.1a, 17.15.2a, 17.15.2c, 17.15.3, 17.15.3a, 17.15.4, 17.15.4c, 17.16.1a, 17.17.1, 17.18.1, 17.18.1a, 17.18.2 | — |
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