VulnerabilityPublished 4 Mar 2026

CVE-2026-20053: Cisco Cyber Vision · Heap-based Buffer Overflow

Affects Cisco Cyber VisionSource CVE Database V5

Compare

Not known to be exploited · CVSS 5.8 Medium.

Data as of 30 Oct 2026, 11:52 UTC

CVSS 3.1 base score

5.8Medium

How severe the flaw is on the 0–10 CVSS scale.

EPSS: 0.4% chance of exploitation in 30 days – higher than 38% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:L

Attack Vector: Network
Attack Complexity: Low
Privileges Required: None
User Interaction: None
Scope: Changed
Confidentiality: None
Integrity: None
Availability: Low

Bold values are the worst case: easiest to exploit or largest impact.

Attack Vector: Network: The vulnerable component is bound to the network stack and the set of possible attackers extends beyond the other options listed, up to and including the entire Internet. Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable at the protocol level one or more network hops away (e.g., across one or more routers).
Attack Complexity: Low: Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.
Privileges Required: None: The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.
User Interaction: None: The vulnerable system can be exploited without any interaction from any user.
Scope: Changed: An exploited vulnerability can affect resources beyond the security scope managed by the security authority of the vulnerable component. In this case, the vulnerable component and the impacted component are different and managed by different security authorities.
Confidentiality: None: There is no loss of confidentiality within the impacted component.
Integrity: None: There is no loss of integrity within the impacted component.
Availability: Low: Performance is reduced or there are interruptions in resource availability. Even if repeated exploitation of the vulnerability is possible, the attacker does not have the ability to completely deny service to legitimate users. The resources in the impacted component are either partially available all of the time, or fully available only some of the time, but overall there is no direct, serious consequence to the impacted component.

Definitions: FIRST CVSS v3.1 specification.

Exploitation evidence

Disclosed: evidence found.
CVE published 4 Mar 2026
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors

A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 30 Oct 2026.

Disclosed: The CVE record is public on cve.org. Its publication is t = 0.
Detectable: A public nuclei template can find exposed instances, for defenders and attackers alike.
Weaponized: A Metasploit exploit module or Exploit-DB entry exists (Metasploit scanner modules do not count), or CISA SSVC or the CVSS exploit maturity reports a public proof of concept.
Exploited in the wild: CISA KEV lists it, CISA SSVC rates exploitation active, or a source reports attacks.
Observed by OffSeq Mirage: OffSeq Mirage honeypot sensors recorded attack traffic for this CVE, or found exposed hosts without attack traffic.

Moments are spaced evenly, not to scale; a dashed line marks a gap of six months or more. Deltas count from t = 0. Sources that give only a date (CISA KEV, Exploit-DB, or a time of exactly 00:00Z) read “same day” rather than hours. Metasploit modules carry the flaw’s disclosure date, not their release date, and nuclei templates carry no date, so both appear above but not on the timeline.

What to do

Affected software

Product	Affected	Fixed in
CiscoCisco Cyber Vision	Affected >=4.2.0 <4.3.0 – 5.3.2 54 affected builds	Fixed in–
CiscoCisco Secure Firewall Threat Defense (FTD) Software	Affected 7.2.0 – 7.7.10.1 37 affected builds	Fixed in–
CiscoCisco UTD SNORT IPS Engine Software	Affected 17.9.4 – 17.18.2 29 affected builds	Fixed in–

AI-suggested

Organizations should immediately assess their Cisco Cyber Vision deployments to identify affected versions ranging from 3.0.0 through 5.3.2. Cisco should be consulted for official patches or updates addressing this vulnerability; applying these updates is the most effective mitigation. In the absence of patches, network-level mitigations such as filtering or blocking suspicious VBA data packets targeting the Snort 3 Detection Engine can reduce exposure. Deploying intrusion prevention systems (IPS) or firewall rules to restrict access to the Snort 3 Detection Engine from untrusted networks is recommended. Monitoring system logs and detection engine stability can help identify exploitation attempts or crashes. Additionally, segmenting the network to isolate Cisco Cyber Vision devices and limiting their exposure to external or less trusted networks can reduce attack surface. Regular backups and failover mechanisms should be tested to ensure rapid recovery from potential DoS conditions. Finally, organizations should maintain up-to-date threat intelligence and monitor Cisco advisories for any emerging exploit information or additional mitigation guidance.

Description

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.

Impact

The primary impact of CVE-2026-20053 is a denial-of-service condition caused by the crashing of the Snort 3 Detection Engine within Cisco Cyber Vision. This can disrupt network monitoring and threat detection capabilities, potentially leaving organizations blind to ongoing or emerging cyber threats. Since Cisco Cyber Vision is often deployed in industrial and critical infrastructure environments for operational technology (OT) visibility, the DoS could affect industrial control systems' security monitoring, increasing the risk of undetected attacks or operational disruptions. Although the vulnerability does not directly compromise confidentiality or integrity, the loss of detection capabilities can indirectly facilitate further attacks or data breaches. The ease of exploitation without authentication or user interaction increases the risk of automated or opportunistic attacks, especially in environments exposed to untrusted networks. Organizations relying heavily on Cisco Cyber Vision for security monitoring may experience operational downtime or degraded security posture until the vulnerability is addressed.

References

sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ftd-snort3-vbavuls-96UcVVed (opens in a new tab)

Community reviews

Loading reviews…

Exploitation evidence

What to do

Affected software

Description

AI analysisMachine-generated, updated 11 Mar 2026, 20:09 UTC

Technical details

References

Community reviews

Related threats