Snort
CVE-2026-20066
MEDIUM
Severity by source
AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L
Primary rating from Vendor (cisco) · only source for this CVE.
CVSS VectorVendor: cisco
Lifecycle Timeline
2DescriptionCVE.org
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 an error in the JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by Snort 3. A successful exploit could allow the attacker to cause a DoS condition when the Snort 3 Detection Engine restarts unexpectedly. JSTokenizer is not enabled by default.
AnalysisAI
Cisco Snort 3 Detection Engine can be remotely restarted by an unauthenticated attacker through crafted HTTP packets exploiting improper JavaScript normalization in the JSTokenizer logic, causing a denial of service condition that interrupts packet inspection. The vulnerability requires the JSTokenizer feature to be enabled and can be triggered via an established network connection without authentication. No patch is currently available.
Technical ContextAI
Classified as CWE-400 (Uncontrolled Resource Consumption). Affects Snort 3 Detection Engine. 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 an error in the JSTokenizer normalization logic when the HTTP inspection normalizes JavaScript. An attacker could exploit this vulnerability by sending crafted HTTP packets through an established connection that is parsed by S
RemediationAI
Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.
Untrusted search path vulnerability in Snort 2.9.7.0-WIN32 allows remote attackers to execute arbitrary code and conduct
Multiple Cisco products are affected by a vulnerability in the rate filtering feature of the Snort detection engine that
Multiple Cisco products are affected by a vulnerability in the way the Snort detection engine processes ICMP traffic tha
Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticate
Multiple Cisco products are affected by a vulnerability in Snort rules that could allow an unauthenticated, remote attac
Cisco Sourcefire Snort 3.0 before build 233 mishandles Ether Type Validation. Rated high severity (CVSS 7.5), this vulne
Multiple Cisco products are affected by a vulnerability in the Snort detection engine that could allow an unauthenticate
Multiple Cisco products are affected by a vulnerability in the Snort Intrusion Prevention System (IPS) rule engine that
Unauthenticated remote attackers can crash the Snort 3 Detection Engine by sending crafted HTTP packets with malformed M
Snort 3 Detection Engine crashes when processing malformed VBA data due to improper decompression error handling, allowi
Denial of service in Cisco Snort 3's VBA decompression feature allows unauthenticated remote attackers to crash the dete
Improper error checking in Cisco Snort 3's VBA decompression feature allows unauthenticated remote attackers to trigger
Same weakness CWE-400 – Uncontrolled Resource Consumption
View allSame technique Denial Of Service
View allShare
External POC / Exploit Code
Leaving vuln.today