Snort
CVE-2026-20053
MEDIUM
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A06:2021 - Vulnerable and Outdated Components
ASVS 5.0
V15 - Secure Coding and Architecture Heap buffer bounds checking
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS 5.8 (MEDIUM). Attack vector: Network. Complexity: Low. Privileges required: None. User interaction: None. Exploitation no authentication required. Exploitable via remote/network. |
| Exploit ScenarioDerived | A remote attacker without authentication could exploit this vulnerability to cause an overflow of heap data, which could cause a DoS condition. |
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Alert meAnalysisAIv1 – Mar 12, 2026
Improper range checking in Cisco Snort 3's VBA decompression feature allows unauthenticated remote attackers to trigger a heap buffer overflow by sending crafted VBA data, causing denial of service. The vulnerability affects multiple Cisco products and requires no authentication or user interaction to exploit. No patch is currently available.
Earlier versions of this analysis (1)
Multiple Cisco products are affected by a vulnerability in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash. This vulnerability is due to improper range checking when decompressing VBA data, which is user controlled. [CVSS 5.8 MEDIUM]
RemediationAI
Monitor vendor advisories for a patch. Restrict network access to the affected service where possible.
Affects your stack
Find out whether the stacks and servers you run are on an affected version.
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
Classified as CWE-122 (Heap-based Buffer Overflow). Affects Snort 3 VBA feature. Multiple Cisco products are affected by a vulnerability in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash.
This vulnerability is due to improper range checking when decompressing VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine on the targeted device. A successful exploit could allow the attacker to cause an overflow of heap d
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- Exploit and PoC references, threat intelligence from 22 sources
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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
DescriptionCVE.org
Multiple Cisco products are affected by a vulnerability in the Snort 3 VBA feature that could allow an unauthenticated, remote attacker to cause the Snort 3 Detection Engine to crash.
This vulnerability is due to improper range checking when decompressing VBA data, which is user controlled. An attacker could exploit this vulnerability by sending crafted VBA data to the Snort 3 Detection Engine on the targeted device. A successful exploit could allow the attacker to cause an overflow of heap data, which could cause a DoS condition.
Executive ViewAI
CVE-2026-20053 presents moderate security risk, a heap-based buffer overflow vulnerability rated CVSS 5.8. Exploitation could cause memory corruption or application crashes. Organizations should apply vendor updates when available and monitor for exploitation.
Apply vendor patch. If patching is delayed: enable ASLR/DEP, apply network segmentation.
Threat Intelligence Overview
NVD
CVE.org
EPSS
VulDB
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
A buffer overflow occurs when a program writes more data to a memory buffer than it was allocated to hold, causing the excess data to spill into adjacent memory regions.
A heap overflow occurs when a program writes data beyond the bounds of a buffer allocated in the heap memory region.
Affected Products (CPE)CVE.org
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Cisco Snort 3 Detection Engine can be remotely restarted by an unauthenticated attacker through crafted HTTP packets exp
Unauthenticated remote attackers can crash the Snort 3 Detection Engine by sending crafted HTTP packets with malformed M
GitHub PoC
Exploit-DB